Tag Archive for: Ransomware

When it comes to protecting your organization from digital threats, who should you trust? Reality dictates that high-resilience IT security is forged from a network of strong partnerships, defense in depth; layered security controls, and regular auditing. Defensive posture needs to be monitored, measured and continuously improved. While vulnerability management has always been a core security control, it is nonetheless a fast moving target. In 2025, continuous and prioritized mitigation of security threats can have a big impact on security outcomes as adversarial time-to-exploit diminishes.

In March 2025’s monthly Threat Report, we will highlight the importance of vulnerability management and Greenbone’s industry leading vulnerability detection by reviewing the most recent critical threats. But these new threats only scratch the surface. In March 2025, Greenbone added 5,283 new vulnerability tests to our Enterprise Feed. Let’s jump into some of the important insights from a highly active threat landscape.

The US Treasury Breach: How Did It Happen?

In late December 2024, the U.S. Treasury Department disclosed that its network was breached by Chinese state-backed hackers and subsequently leveraged sanctions in early January 2025. Forensic investigations have tracked the root-cause to a stolen BeyondTrust API key. The vendor has acknowledged 17 other customers breached by this flaw. Deeper investigation has revealed that the API key was stolen via a flaw in a PostgreSQL built-in function for escaping untrusted input.

When invalid two-byte UTF-8 characters are submitted to a vulnerable PostgreSQL function, only the first byte is escaped, allowing a single quote to pass through unsanitized which can be leveraged to trigger an SQL Injection [CWE-89] attack. The exploitable functions are PQescapeLiteral(), PQescapeIdentifier(), PQescapeString() und PQescapeStringConn(). All versions of PostgreSQL before 17.3, 16.7, 15.11, 14.16, and 13.19 are affected as well as numerous products that depend on these functions.

CVE-2024-12356, (CVSS 9.8) and CVE-2024-12686, (CVSS 7.2) have been issued for BeyondTrust Privileged Remote Access (PRA) and Remote Support (RS) and CVE-2025-1094 (CVSS 8.1) addresses the flaw in PostgreSQL. The issue is the subject of several national CERT advisories including Germany’s BSI Cert-Bund (WID-SEC-2024-3726) and the Canadian Centre for Cybersecurity (AV25-084). The flaw has been added to CISA’s known exploited vulnerabilities (KEV) list, and a Metasploit module that exploits vulnerable BeyondTrust products is available, increasing the risk. Greenbone is able to detect the CVEs (Common Vulnerabilities and Exposures) discussed above both in BeyondTrust products or instances of PostgreSQL vulnerable to CVE-2025-1094.

Advanced fined 3.1 Million Pound for Lack of Technical Controls

This month, the UK’s Information Commissioner’s Office (ICO) imposed a 3.07 million Pound fine on Advanced Computer Software Group Ltd. under the UK GDPR for security failures. The case is evidence of how the financial damage caused by a ransomware attack can be further exacerbated by regulatory fines. The initial proposed amount was even higher at 6.09 million Pound. However, since the victim exhibited post-incident cooperation with the NCSC (National Cyber Security Centre), NCA (National Crime Agency) and NHS (National Health Service), a voluntary settlement of 3,076,320 Pound was approved. While operational costs and extortion payments have not been publicly disclosed, they likely add between 10 to 20 million Pound to the incident’s total costs.

Advanced is a major IT and software provider to healthcare organizations including the NHS. In August 2022, Advanced was compromised, attackers gained access to its health and care subsidiary resulting in a serious ransomware incident. The breach disrupted critical services including NHS 111 and prevented healthcare staff from accessing personal data on 79,404 individuals, including sensitive care information.

The ICO concluded that Advanced had incomplete MFA coverage, lacked comprehensive vulnerability scanning and had deficient patch management practices at the time of the incident – factors that collectively represented a failure to implement appropriate technical and organizational measures. Organizations processing sensitive data must treat security controls as non-negotiable. Inadequate patch management remains one of the most exploited gaps in modern attack chains.

Double Trouble: Backups Are Critical to Ransomware Mitigation

Backups are an organization’s last defense against ransomware and most sophisticated advanced persistent threat (APT) actors are known to target their victim’s backups. If a victim’s backups are compromised, submission to ransom demands is more likely. In 2025, this could mean multi-million Dollar losses. In March 2025, two new significant threats to backup services were revealed; CVE-2025-23120, a new critical severity flaw in Veeam was disclosed, and campaigns targeting CVE-2024-48248 in NAKIVO Backup & Replication were observed. Identifying affected systems and patching them is therefore an urgent matter.

In October 2024, our threat report alerted about another vulnerability in Veeam (CVE-2024-40711) being used in ransomware attacks. Overall, CVEs in Veeam Backup and Replication have a high conversion rate for active exploitation, PoC (Proof of Concept) exploits, and use in ransomware attacks. Here are the details for both emerging threats:

  • CVE-2024-48248 (CVSS 8.6): Versions of NAKIVO Backup & Replication before 11.0.0.88174 allow unauthorized Remote Code Execution (RCE) via a function called getImageByPath which allows files to be read remotely. This includes database files containing cleartext credentials for each system that NAKIVO connects to and backs up. A full technical description and proof-of-concept is available and this vulnerability is now tracked as actively exploited.
  • CVE-2025-23120 (CVSS 9.9): Attackers with domain user access can trigger deserialization of attacker-controlled data through the .NET Remoting Channel. Veeam attempts to restrict dangerous types via a blacklist, but researchers discovered exploitable classes (xmlFrameworkDs and BackupSummary) not on the list. These extend .NET’s DataSet class – a well-known RCE vector – allowing arbitrary code execution as SYSTEM on the backup server. The flaw is the subject of national CERT alerts globally including HK, CERT.be, and CERT-In. As per Veeam’s advisory, upgrading to version 12.3.1 is the recommended way to mitigate the vulnerability.

Greenbone is able to detect vulnerable NAKIVO and Veeam instances. Our Enterprise Feed has an active check [1] and version check [2] for CVE-2024-48248 in NAKIVO Backup & Replication, and a remote version check [3] for the Veeam flaw.

IngressNightmare: Unauthenticated Takeover in 43% of Kubernetes Clusters

Kubernetes is the most popular enterprise container orchestration tool globally. Its Ingress feature is a networking component that manages external access to services within a cluster, typically HTTP and HTTPS traffic. A vulnerability dubbed IngressNightmare has exposed an estimated 43% of Kubernetes clusters to unauthenticated remote access – approximately 6,500 clusters, including Fortune 500 companies.

The root-cause is excessive default privileges [CWE-250] and unrestricted network accessibility [CWE-284] in the Ingress-NGINX Controller tool, based on NGINX reverse proxy. IngressNightmare allows attackers to gain complete unauthorized control over workloads, APIs or sensitive resources in multi-tenant and production-grade clusters. A full technical analysis is available from the researchers at Wiz, who pointed out that K8 Admission Controllers are directly accessible without authentication by default, presenting an appealing attack surface to hackers.

The full attack trajectory to achieve arbitrary RCE against an affected K8 instance requires exploiting Ingress-NGINX. First, CVE-2025-1974 (CVSS 9.8) to upload a binary payload as the request body. It should be larger than 8kb in size while specifying a Content-Length header larger than the actual content size. This triggers NGINX to store the request body as a file, and the incorrect Content-Length header means the file will not be deleted as the server waits for more data [CWE-459].

The second stage of this attack requires exploiting CVE-2025-1097, CVE-2025-1098, or CVE-2025-24514 (CVSS 8.8). These CVEs all similarly fail to properly sanitize input [CWE-20] submitted to Admission Controllers. Ingress-NGINX converts Ingress objects to configuration files and validates them with the nginx -t command, allowing attackers to execute a limited set of NGINX configuration directives. Researchers found the ssl_engine module can be triggered to load the shared library binary payload uploaded in the first stage. Although exploitation is not trivial and no public PoC code exists yet, sophisticated threat actors will easily convert the technical analysis into effective exploits.

The Canadian Centre for Cyber Security has issued a CERT advisory (AV25-161) for IngressNightmare. Patched Ingress-NGINX versions 1.12.1 and 1.11.5 are available and users should upgrade as soon as possible. If upgrading the Ingress NGINX Controller is not immediately possible, temporary workarounds can help reduce risk. Strict network policies can restrict access to a cluster’s Admission Controllers allowing access to only the Kubernetes API Server. Alternatively, the Admission Controller component of Ingress-NGINX can be disabled entirely.

Greenbone is able to detect IngressNightmare vulnerabilities with an active check that verifies the presence of all CVEs mentioned above [1][2].

CVE-2025-29927: Next.js Framework Under Attack

A new vulnerability in Next.js, CVE-2025-29927 (CVSS 9.4) is considered high risk due the framework’s popularity and the simplicity of exploitation [1][2]. Adding to the risk, PoC exploit code is publicly available and Akamai researchers have observed active scans probing the Internet for vulnerable apps. Several national CERTs (Computer Emergency Response Teams) have issued alerts for the issue including CERT.NZ, Australian Signals Directorate (ASD), Germany’s BSI Cert-Bund (WID-SEC-2025-062), and the Canadian Centre for Cyber Security (AV25-162).

Next.js is a React middleware framework for building full-stack web applications. Middleware refers to components that sit between two or more systems and handle communication and orchestration. For web-applications, middleware converts incoming HTTP requests into responses and is often also responsible for authentication and authorization. Due to CVE-2025-29927, attackers can bypass Next.js middleware authentication and authorization simply by setting a malicious HTTP header.

If using HTTP headers seems like a bad idea for managing a web application’s internal process flow, CVE-2025-29927 is the evidence. Considering user-provided headers were not correctly distinguished from internal ones, this vulnerability should attain the status of egregious negligence. Attackers can bypass authentication by simply adding the `x‑middleware‑subrequest` header to a request and overloading it with at least as many values as the MAX_RECURSION_DEPTH which is 5. For example:

`x-middleware-subrequest: middleware:middleware:middleware:middleware:middleware`

The flaw is fixed in Next.js versions 15.2.3, 14.2.25, 13.5.9 and 12.3.5, and users should follow the vendor’s upgrade guide. If upgrading is infeasible, it is recommended to filter the `x-middleware-subrequest` header from HTTP requests. Greenbone is able to detect vulnerable instances of Next.js with an active check and a version check.

Summary

The March 2025 threat landscape was shaped by vulnerable and actively exploited backup systems, unforgivably weak authentication logic, high-profile regulatory fines and numerous other critical software vulnerabilities. From the U.S. Treasury breach to the Advanced ransomware fallout, the theme is clear: trust doesn’t grow on trees. Cybersecurity resilience must be earned; forged through layered security controls and backed up by accountability.

Greenbone continues to play a vital role by providing timely detection tests for new emerging threats and standardized compliance audits that support a wide array of enterprise architectures. Organizations that want to stay ahead of cyber crime need to proactively scan their infrastructure and close security gaps as they appear.

CVE-2024-4577 (CVSS 9.8 Critical) is currently climbing the winners’ podium of the most malicious security vulnerabilities. Disclosed in early June 2024 by Devcore security researchers, weaponization began within a mere 48 hours. It is a PHP-CGI OS Command Injection vulnerability [CWE-78] impacting PHP for Windows. Attacks distributing “TellYouThePass” ransomware were immediately observed and the CVE added to CISA’s KEV list (Known Exploited Vulnerabilities of the Cybersecurity and Infrastructure Security Agency). Several months later, exploitation of CVE-2024-4577 suddenly continues to escalate.

Greenbone provided vulnerability tests (VTs) to detect systems impacted by CVE-2024-4577 since it was released in June 2024. This allows defenders to identify affected systems across public-facing or internal network infrastructure. Let’s look deeper into the threat of CVE-2024-4577.

Exploiting CVE-2024-4577 for RCE and Lateral Movement

Proof of concept (PoC) exploit code and a full technical breakdown has long been published by watchTowr Labs, and a Metasploit module was also released in mid-2024. National CERT advisories have recently been issued by CERT New Zealand (CERT NZ) and the Canadian Center for Cyber Security. However, the flaw had already been alerted by CERT-EU, and CERT-FR (French Government CERT) back in June 2024.

Due to CVE-2024-4577, the PHP-CGI (Common Gateway Interface) may misinterpret certain characters as PHP options, which may allow a malicious user to pass options to the php.exe binary. This trick can reveal the source code of scripts or run arbitrary PHP code on the server. CVE-2024-4577 is considered a bypass of a long-ago patched vulnerability in PHP, CVE-2012-1823.

In the case that attackers gain initial access to a victim’s network through social engineering or a different software vulnerability, CVE-2024-4577 can provide an attacker with the opportunity for lateral movement, or covert persistence, penetrating deeper into a victim’s infrastructure and increasing the blast radius of a cyber attack.

A Brief Technical Explanation of CVE-2024-4577

In a nutshell, exploitation of CVE-2024-4577 works by leveraging Unicode character conversion to inject malicious command-line arguments to the php.exe process. On a high-level, web servers behave differently when CGI mode is enabled. A webserver will normally parse HTTP requests and pass them to a PHP script for processing. However, when CGI mode is enabled, attributes are extracted from the URL and passed as arguments to the executable PHP binary (php.exe on Windows). This PHP-CGI process is known to introduce distinct security risks.

Although PHP-GCI is supposed to sanitize shell meta characters (such as hyphens, double-hyphens, ampersands, and equal signs) before being passed, this still opens a pathway to command injection if attackers can find a way to bypass the sanitization process. PHP-CGI encoding was also the target of exploiting CVE-2012-1823. Furthermore, similar character encoding battles are continuously waged resulting in new ways for attackers to execute XSS and SQL injection vulnerabilities.

In the current iteration of this attack, using a soft hyphen (0xAD) instead of a standard hyphen (0x2D), attackers can initiate PHP directives to achieve Remote Code Execution (RCE). This is because Windows uses the UCS-2 character set, converts all characters to the UCS-2 code-point value and also executes an additional “best-fit” conversion. In the case of CVE-2024-4577, it is the best-fit schema that converts soft hyphens into standard hyphens. This allows injecting php.exe with arguments to prepend and execute the HTTP request body itself by adding the command “-d allow_url_include=1 -d auto_prepend_file=php://input” using URL encoded soft hyphens to the HTTP GET string. Soft hyphens are typically invisible UTF-8 characters used to specify locations word breaks, but only when necessary to fit the text on the line. Thanks to Windows’ best-fit conversion, they are effectively converted into command line flags.

CVE-2024-4577 is Being Leveraged Globally in 2025

According to new reports released in March 2025, attacks leveraging CVE-2024-4577 are ongoing,  widespread and escalating. Cisco detected exploitation of CVE-2024-4577 in January 2025, targeting Japanese education, ecommerce and telecommunications companies. After gaining initial access via PHP, attackers installed Cobalt Strike’s ‘TaoWu’ plugins and modified Windows registry keys to establish persistent access through scheduled tasks.

Another recent report from GreyNoise reveals that mass exploitation of CVE-2024-4577 has extended to targets in the US, UK, Singapore, Indonesia, Taiwan, Hong Kong, India, Spain and Malaysia. Germany and China were reportedly the primary sources of attacks, accounting for 43% globally. GreyNoise also maintains a honeynet that detected over 1,089 unique IPs attempting exploitation in January 2025 alone, and counted 79 publicly available, specialized exploit kits. The cybersecurity firm warned of growing attack volume in February 2025, driven by automated scanning and signaling a rapidly escalating cyber threat.

Mitigation for CVE-2024-4577

CVE-2024-4577 affects all PHP versions (including PHP 5 and PHP 7 which are end-of-life) before 8.1.29, 8.2.20 and 8.3.8 on Windows. The best mitigation is to upgrade to a patched version with urgency. For environments where immediate patching isn’t feasible, defenders may disable the execution of PHP-CGI mode in favor of PHP-FPM (FastCGI Process Manager) or alternatively, utilize a web-application firewall (WAF) to filter and block exploitation attempts. PHP system administrators should also note several additional security risks associated with CGI and review them for optimal security.

Greenbone has provided vulnerability tests (VTs) to detect systems impacted by CVE-2024-4577 since it was first disclosed in June 2024. This early detection capability allows defenders to identify affected systems across public facing or internal network infrastructure. Greenbone’s detection tests include remote version detections [1][2], and a remote active check [3].

Summary

CVE-2024-4577 is a critical PHP-CGI vulnerability affecting PHP installations on Windows, that allows remote code execution (RCE). The flaw was weaponized within 48 hours of disclosure and used in TellYouThePass ransomware attacks. According to reports from Cisco and GreyNoise, mass exploitation of CVE-2024-4577 has been escalating globally, and multiple national CERT advisories have been issued. Defenders need to identify where affected products are operating within their infrastructure, and immediately update to a fixed version of PHP, disable PHP-CGI completely or switch to PHP-FPM (FastCGI Process Manager).

Cyber threats are evolving at breakneck speed, but the fundamental weaknesses attackers exploit remain strikingly unchanged. So far in 2025, many analysts have published landscape reviews of 2024 and outlooks for 2025. The cost of cyber breaches is ticking upwards, but overall, cyber breach root-causes have not changed. Phishing [T1566] and exploiting known software vulnerabilities [T1190] continue to top the list. Another key observation is that attackers are weaponizing public information faster, converting CVE (Common Vulnerabilities and Exposures) disclosures into viable exploit code within days or even hours. Once inside a victim’s network, they are executing precision second-stage objectives faster too, deploying ransomware within minutes.

In this month’s edition of the Greenbone Threat Report, we will briefly review the disclosed chats of the Black Basta ransomware group and highlight Greenbone’s coverage of their now exposed techniques. We will also review a report from Greynoise about mass exploitation attacks, a new actively exploited vulnerability in Zimbra Collaboration Suite and new threats to edge networking devices.

The Era of Tectonic Technology

If security crises are like earthquakes, then the global tech ecosystem is the underlying tectonic plates. The global technology ecosystem would be best represented as the Paleozoic Era of geological history. Rapid innovative and competitive market forces are pushing and pulling at the fabric of IT security like the colliding supercontinents of Pangea; continuous earthquakes constantly forcing continental shift.

Entirely new paradigms of computing such as generative AI and quantum computing are creating advantages and risks; volcanoes of value and unstable ground. Global governments and tech giants are wresting for access to citizen’s sensitive personal data, adding gravity. These struggles have significant implications for privacy, security and how society will evolve. Here are some of the major forces destabilizing IT security today:

  • Rapidly evolving technologies are driving innovation, forcing technical change.
  • Organizations are both forced to change as technologies and standards depreciate and motivated to change to remain competitive.
  • Fierce market competition has accelerated product development and release cycles.
  • Strategic planned obsolescence has been normalized as a business strategy for reaping financial gain.
  • Pervasive lack of accountability for software vendors has led to prioritization of performance over “security-first” design principles.
  • Nation-states weaponize technology for Cyber Warfare, Information Warfare and Electronic Warfare.

Due to these forces, well-resourced and well-organized cyber criminals find a virtually unlimited number of security gaps to exploit. The Paleozoic Era lasted 300 million years. Hopefully, we won’t have to wait that long for product vendors to show accountability and employ secure design principles [1][2][3] to prevent so-called “unforgivable” vulnerabilities of negligence [4][5]. The takeaway is that organizations need to develop technical agility and efficient patch management programs. Continuous prioritized vulnerability management is a must.

Black Basta Tactics Revealed: Greenbone Has Coverage

Leaked internal chat logs belonging to Black Basta ransomware group have provided insight into the group’s tactics and inner workings. The logs were leaked by an individual using the alias “ExploitWhispers” who claimed the release was in response to Black Basta’s controversial targeting of Russian banks, allegedly creating internal conflicts within the group. Since its emergence in April 2022, Black Basta has reportedly amassed over $100 million in ransom payments from more than 300 victims worldwide. 62 CVEs referenced in leaked documents reveal the group’s tactics for exploiting known vulnerabilities. Of these 62, Greenbone maintains detection tests for 61, covering 98% of the CVEs.

The Greynoise 2025 Mass Exploitation Report

Mass exploitation attacks are fully automated network attacks against services that are accessible via internet. This month, Greynoise published a comprehensive report summarizing the mass exploitation landscape including the top CVEs attacked by the largest botnets (unique IPs), the most exploited product vendors and top CVEs included in the CISA’s (Cybersecurity and Infrastructure Security Agency) KEV (Known Exploited Vulnerabilities) catalog and exploited by botnets. Greenbone Enterprise Feed has detection tests for 86% of all CVEs (86 total) referenced in the report. When considering only CVEs issued in 2020 or later (66 total), our Enterprise Feed has 90% detection coverage.

Additional findings include:

  • 60% of CVEs exploited in mass exploitation attacks were published in 2020 or later.
  • Attackers are exploiting vulnerabilities within hours of disclosure.
  • 28% of vulnerabilities in CISA KEV are exploited by ransomware threat actors.

Zimbra Collaboration Suite

CVE-2023-34192 (CVSS 9.0) is a high-severity Cross-Site Scripting (XSS) vulnerability in Zimbra Collaboration Suite (ZCS) version 8.8.15. The flaw allows authenticated remote attackers to execute arbitrary code via crafted scripts targeting the `/h/autoSaveDraft` function. CISA added CVE-2023-34192 to its KEV catalog, indicating that it has been actively exploited in real-world attacks. Proof-of-concept (PoC) exploit code is publicly available, allowing low-skilled attackers to join the fray. CVE-2023-34192 has held a very high EPSS since its disclosure in 2023. For defenders leveraging EPSS for remediation prioritization, this indicates a high priority to patch.

Zimbra Collaboration Suite (ZCS) is an open-source office productivity platform that integrates email, calendar, contacts, tasks and collaboration tools but holds a niche market share of less than 1% of all email and messaging platforms.

Living on the Edge: New Critical Networking Device Flaws

In our monthly threat report we have been tracking the persistent threat to edge network devices. Earlier this-month, we reported on a perfect security storm affecting end-of-life (EOL) Zyxel routers and firewalls. In this section we will review new security risks that fall into the “edge networking” category. Greenbone has detection capabilities for all CVEs discussed below.

Chinese Hackers Exploit Palo Alto’s PAN-OS for Ransomware

CVE-2024-0012 (CVSS 9.8), a vulnerability in Palo Alto PAN-OS disclosed last November, is considered one of the most exploited vulnerabilities of 2024. The CVE is also reportedly being used by Chinese state-backed threat actors for ransomware attacks. Another new flaw affecting PAN-OS, CVE-2025-0108 (CVSS 9.1), was just disclosed this month and immediately tagged as actively exploited by CISA. CVE-2025-0108 is an authentication bypass in the management web-interface and can be chained together with CVE-2024-9474 (CVSS 7.2), a separate privilege escalation vulnerability to gain unauthenticated root control over an unpatched PAN-OS device.

SonicWall Patches a Critical Actively Exploited CVE in SonicOS

CVE-2024-53704, a critical severity vulnerability in SonicWall devices, has been recently added to CISA’s KEV list. Astoundingly, CISA lists 8 SonicWall CVEs that are known to be actively exploited in ransomware attacks. CVE-2024-53704 (CVSS 9.8) is an Improper Authentication vulnerability [CWE-287] in the SSLVPN authentication mechanism of SonicWall’s SonicOS versions 7.1.1-7058 and older, 7.1.2-7019, and 8.0.0-8035. It allows remote attackers to bypass authentication and and hijack active SSL VPN sessions, potentially gaining unauthorized network access. A full technical analysis is available from BishopFox. An advisory from SonicWall also names additional high severity CVEs in SonicOS that have been patched along with CVE-2024-53704.

Sophos’ CyberroamOS and EOL XG Firewalls Actively Exploited

Sophos, which acquired Cyberoam in 2014, has issued an alert and patch for CVE-2020-29574. CyberoamOS is part of Sophos’ product ecosystem. Aside from this CVE, Sophos XG Firewall, soon to be EOL, is also the subject of an active exploitation alert.

  • CVE-2020-29574 (CVSS 9.8): A critical SQL injection [CWE-89] vulnerability identified in the WebAdmin interface of CyberoamOS versions up to December 4, 2020. This flaw allows unauthenticated attackers to remotely execute arbitrary SQL statements, potentially gaining complete administrative access to the device. A hotfix patch has been issued, which also extends to some affected end-of-life (EOL) products.
  • CVE-2020-15069 (CVSS 9.8) is a critical Buffer Overflow vulnerability in Sophos XG Firewall versions 17.x through v17.5 MR12, allowing unauthenticated RCE via the HTTP/S Bookmarks feature for clientless access. This vulnerability, published in 2020 is now being actively exploited and has been added to CISA KEV indicating heightened risk. Sophos released an advisory in 2020 when the vulnerability was disclosed, along with a hotfix affected firewalls. The XG Series hardware appliances are soon scheduled to reach end-of-life (EOL) on March 31, 2025.

PrivEsc and Auth Bypasses in Fortinet FortiOS and FortiProxy

Fortinet disclosed two critical vulnerabilities, both affecting FortiOS and FortiProxy. The Canadian Center for Cybersecurity and the Belgian Center for Cybersecurity have issued advisories. Fortinet acknowledges active exploitation of CVE-2024-55591 and has released official guidance that includes details on affected versions and recommended updates. ​

  • CVE-2024-55591 (CVSS 9.8): An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS allows a remote attacker to gain super-admin privileges via crafted requests to Node.js websocket module. Multiple PoC exploits are available [1][2] increasing the risk of exploitation by low-skilled attackers.
  • CVE-2024-40591 (CVSS 8.8): Allows an authenticated administrator with Security Fabric permissions to escalate their privileges to super-admin by connecting the targeted FortiGate device to a malicious upstream FortiGate under their control.

Cisco Flaws Implicated as Initial Access Vectors in Telecom Hacks

In the past few months, China’s Salt Typhoon espionage group has routinely exploited at least two critical vulnerabilities in Cisco IOS XE devices to gain persistent access to telecommunications networks. Victims include Italian ISP, a South African telecom, and a large Thai telecom, and twelve universities worldwide including UCLA, Indonesia’s Universitas Negeri Malang and Mexico’s UNAM among others. Previously, Salt Typhoon had compromised at least nine U.S. telecoms, including Verizon, AT&T and Lumen Technologies. U.S. authorities claim Salt Typhoon’s goal is surveilling high-profile individuals, political figures and officials related to Chinese political interests.

CVEs exploited by Salt Typhoon include:

  • CVE-2023-20198 (CVSS 10): A privilege escalation flaw in Cisco IOS XE’s web interface. Used for initial access, allowing attackers to create an admin account.
  • CVE-2023-20273 (CVSS 7.2): Another privilege escalation flaw, used after gaining admin access to escalate privileges to root and establish a GRE (Generic Routing Encapsulation) tunnel for persistence.

Also, two other CVEs in Cisco products entered the radar in February 2025:

  • CVE-2023-20118 (CVSS 7.2): A command injection vulnerability in the web-based management interface of Cisco Small Business Routers allows authenticated, remote attackers to execute arbitrary commands with root-level privileges by sending crafted HTTP requests. CISA added CVE-2023-20118 to its KEV catalog, indicating evidence of active exploitation.
  • CVE-2023-20026 (CVSS 7.2): A command injection vulnerability in the web-based management interface of Cisco Small Business Routers RV042 Series allows authenticated, remote attackers with valid administrative credentials to execute arbitrary commands on the device. The flaw is due to improper validation of user input within incoming HTTP packets. While CVE-2023-20026 is not known to be exploited in any active campaigns, Cisco’s Product Security Incident Response Team (PSIRT) is aware that PoC exploit code for this vulnerability exists.

Ivanti Patches Four Critical Flaws

Four critical vulnerabilities were identified, affecting Ivanti Connect Secure (ICS), Policy Secure (IPS), and Cloud Services Application (CSA). No reports of active attacks in the wild or PoC exploits have emerged yet. Ivanti advises users to promptly update to the newest versions to address these critical vulnerabilities.

Here is a brief technical summary:

  • CVE-2025-22467 (CVSS 8.8): Attackers with credentials can achieve remote code execution (RCE) due to a stack-based buffer overflow [CWE-121] flaw in ICS versions prior to 22.7R2.6.
  • CVE-2024-38657 (CVSS 9.1): Attackers with credentials can write arbitrary files due to an external control of file name vulnerability in ICS versions before 22.7R2.4 and IPS versions before 22.7R1.3.
  • CVE-2024-10644 (CVSS 9.1): A code injection flaw in ICS (pre-22.7R2.4) and IPS (pre-22.7R1.3), allows arbitrary RCE to authenticated administrators. ​
  • CVE-2024-47908 (CVSS 7.2): An operating system command injection vulnerability [CWE-78] in CSA’s admin web console (versions before 5.0.5), allows arbitrary RCE to authenticated administrators.

Summary

This month’s Threat Report highlights key cybersecurity developments, including the evolving tactics of ransomware groups like Black Basta and the pervasive critical threat to edge network devices. With the support of AI tools, attackers are exploiting vulnerabilities faster-sometimes within hours of disclosure. Organizations must remain vigilant by adopting proactive security measures, continuously updating their defenses and leveraging threat intelligence to stay ahead of emerging threats.

Every product has a due date, but customers often have little warning and no recourse when a vendor decides to sunset a product. Once a vendor designates a product as end-of-life (EOL) or end-of-service (EOS), managing associated risks becomes more complex. Risk is magnified when cyber criminals find and exploit vulnerabilities that will never be patched. If an EOL product becomes vulnerable in the future, its users need to implement additional security controls on their own.

Digital illustration of storm clouds and a trash bin with a router symbol, representing end-of-life IT products and increasing ransomware risks.

If the vendor is found to be still selling these vulnerable EOL products, it may be considered the “perfect storm” or the maximum disaster. In this article we will investigate several security alerts for Zyxel products including some designated EOL and another flaw exploited in ransomware attacks.

An Overview of Recent Vulnerabilities in Zyxel Products

CVE-2024-40891 (CVSS 8.8), a high severity Remote Code Execution (RCE) flaw in Zyxel’s telnet implementation has been known since mid-2024. Yet, almost six months later, Zyxel has not issued a patch, claiming the affected products are EOS and EOL. Early in 2025, Greynoise observed active exploitation of CVE-2024-40891 against vulnerable Zyxel CPE networking devices. That CVE (Common Vulnerabilities and Exposures) and another RCE flaw, CVE-2024-40890 (CVSS 8.8), were both added to CISA’s Known Exploited Vulnerabilities (KEV) list by mid-February. While both CVEs (Cybersecurity and Infrastructure Security Agency) were post-authentication RCE flaws, a third security gap, CVE-2025-0890 (CVSS 9.8), published on February 4th, provided the final piece to the puzzle: extremely weak default credentials for remotely accessible services – that is, on top of the already unencrypted Telnet authentication process.

Researchers at VulnCheck who originally discovered the flaws also pointed out that the vendor continues to sell the faulty devices despite being aware of active exploitation and having no intention to issue patches. As of February 25th, 2025, some of the affected products were still being sold from Zyxel’s official Amazon store [1][2]. On top of these, another vulnerability in Zyxel products, CVE-2024-11667, is being actively exploited in ransomware attacks by the Helldown threat actor.

In the telecom technologies sector, Zyxel holds an estimated market share of 4.19%, serving around 2,277 companies including the world’s biggest tech giants. Zyxel Group, headquartered in Hsinchu Science Park, Taiwan, is a prominent provider of networking solutions for both businesses and home users, operating globally in over 150 countries.

A Timeline of Events

  • 2024-07-13: VulnCheck notified Zyxel about vulnerabilities in CPE series products.
  • 2024-07-31: VulnCheck published information about CVE-2024-40890 and CVE-2024-40891 on their blog.
  • 2025-01-28: Active exploitation of CVE-2024-40891 was reported by GreyNoise.
  • 2025-02-03: VulnCheck released further information highlighting the risk presented by Zyxel’s position and providing evidence that vulnerable devices were still being sold online by the vendor.
  • 2025-02-04: Zyxel released a security advisory labelling affected products as EOL and stating they will not receive updates.

Technical Descriptions of Recent Zyxel Vulnerabilities

Aside from Zyxel’s slow response to security researchers and their decision to continue selling EOL products with exploitable vulnerabilities, there are additional lessons to learn from a technical assessment of the flaws themselves. Namely, how product vendors continue to market products with unforgivable security flaws while skirting accountability.                                                                                

  • CVE-2024-40891 (CVSS 8.8 High): Authenticated users can exploit Telnet command injection due to improper input validation in `libcms_cli.so`. Commands are passed unchecked to a shell execution function, allowing arbitrary RCE. Aside from checking that the command string starts with an approved command, the `prctl_runCommandInShellWithTimeout` function has no filtering, allowing command chaining and arbitrary command injection.
  • CVE-2024-40890 (CVSS 8.8 High): A post-authentication command injection vulnerability in the CGI program of the legacy DSL Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an authenticated attacker to execute operating system (OS) commands on an affected device by sending a crafted HTTP POST request.
  • CVE-2025-0890 (CVSS 9.8 Critical): Devices use weak default credentials such as usernames and passwords admin:1234, zyuser:1234, and supervisor:zyad1234. None of these accounts are visible via the web interface but can be found in the device’s `/etc/default.cfg` These default credentials are now well-known by attackers. The “supervisor” and “zyuser” accounts can both access devices remotely via Telnet. “supervisor” has hidden privileges, granting full system access, while “zyuser” can still exploit CVE-2024-40891 for RCE. Use of such default credentials violate CISA’s Secure by Design pledge and the EU’s upcoming Cyber Resilience Act (CRA).

The affected products include Zyxel VMG1312-B Series (VMG1312-B10A, VMG1312-B10B, VMG1312-B10E, VMG3312-B10A, VMG3313-B10A, VMG3926-B10B, VMG4325-B10A, VMG4380-B10A, VMG8324-B10A, VMG8924-B10A) and two Zyxel Business Gateway Series routers (SBG3300, and SBG3500). The Zyxel CPE (Customer Premises Equipment) series devices are designed for home and small business internet connectivity, such as DSL, fiber and wireless gateways. As such, they are typically installed at a customer’s location to connect them to an Internet  Service Provider’s (ISP) network and are therefore not easily protected from the Internet by firewalls. Considering the nature of Zyxel CPE devices and the vulnerabilities in question, it would not be surprising if tens of thousands or more Zyxel devices were participating in malicious botnet activity.

Greenbone is able to detect EOL Zyxel devices that are vulnerable to the aforementioned CVEs.

CVE-2024-11667: Zyxel Firewalls Exploited in Ransomware Attacks

CVE-2024-11667 (CVSS 9.8 Critical), published in late December 2024, is a path traversal flaw [CWE-22] in the web-management console of Zyxel ATP and USG FLEX firewall series. The vulnerability is known to be exploited by the Helldown threat actor in ransomware attacks and the subject of several national cybersecurity advisories [1][2].

The Helldown ransomware group emerged in August 2024 as a notable threat actor in the cybersecurity landscape. This group employs a double extortion strategy, wherein they exfiltrate sensitive data from targeted organizations and subsequently deploy ransomware to encrypt the victims’ systems. If the ransom demands are not met, Helldown threatens to publicly release the stolen data on their data leak site. In addition to exploiting these Zyxel flaws, Helldown is known to exploit Windows OS vulnerabilities, VMware ESX,  and Linux environments, often using compromised VPN credentials to move laterally within networks.

Zyxel has released an advisory acknowledging the ransomware attacks and patches for affected products. Greenbone is able to detect Zyxel products affected by CVE-2024-11667 with three separate product specific version detection tests [1][2][3].

Summary

The situation with Zyxel seems to be a perfect storm leading to an important question: What recourse do customers have when a vendor fails to patch a security gap in their product? Zyxel’s EOL networking devices remain actively exploited, with vulnerabilities that can be combined for unauthorized arbitrary RCE and other unauthorized actions. CVE-2024-40891, CVE-2024-40890, and CVE-2025-0890 are now in CISA’s KEV list, while CVE-2024-11667 has been linked to ransomware attacks. The researchers from VulnCheck, who discovered several of these CVEs, have criticized Zyxel for poor communication and further for selling unpatched EOL devices. Greenbone detects affected products enabling a proactive approach to vulnerability management and the opportunity for users to mitigate exposure.

This year, many large organizations around the world will be forced to reckon with the root-cause of cyber intrusions. Many known vulnerabilities are an open gateway to restricted network resources. Our first Threat Report of 2025 reviews some disastrous breaches from 2024 and then dives into some pressing cybersecurity vulnerabilities from this past month.

However, to be clear, the vulnerabilities discussed here merely scratch the surface. In January 2025, over 4,000 new CVEs (Common Vulnerabilities and Exposures) were published; 22 with the maximum CVSS score of 10, and 375 rated critical severity. The deluge of critical severity flaws in edge networking devices has not abated. Newly attacked flaws in products from global tech giants like Microsoft, Apple, Cisco, Fortinet, Palo Alto Networks, Ivanti, Oracle and others have been appended to CISA’s (Cybersecurity and Infrastructure Security Agency) Known Exploited Vulnerabilities (KEV) catalog.

Software Supply Chain: the User’s Responsibility

We are all running software we didn’t design ourselves. This places a huge emphasis on trust. Where trust is uncertain – whether due to fears of poor diligence, malice or human error – cybersecurity responsibility still rests on the end-user. Risk assurances depend heavily on technical knowledge and collective effort. Defenders need to remember these facts in 2025.

When supply chain security fails, ask why! Did the software vendor provide the required tools to take control of your own security outcomes? Is your IT security team executing diligent vulnerability discovery and remediation? Are your resources segmented with strong access controls? Have employees been trained to identify phishing attacks? Are other reasonable cybersecurity measures in place? Organizations need to mature their ransomware-readiness, implement regular vulnerability assessments and prioritized patch management. And they should verify reliable backup strategies can meet recovery targets and prioritize other fundamental security controls to protect sensitive data and prevent downtime.

Fortune Favors the Prepared

Assessing 2024, the UK’s NCSC (National Cyber Security Center) annual review painted a grim picture; significant cyberattacks had increased three times compared to 2023. For a birds-eye view, CSIS (The Center for International Strategic & International Studies) has posted an extensive list of the most significant cyber incidents of 2024. The landscape has been shaped by the Russia Ukraine conflict and an accelerated shift from globalization to adversarialism.

Check Point Research found that 96% of all vulnerabilities exploited in 2024 were over a year old. These are positive findings for proactive defenders. Entities conducting vulnerability management will fare much better against targeted ransomware and mass exploitation attacks. One thing is clear: proactive cybersecurity reduces the cost of a breach.

Let’s review two of the most significant breaches from 2024:

  • The Change Healthcare Breach: Overall in 2024, breaches of healthcare entities were down from 2023’s record setting year. However, the ransomware attack against Change Healthcare set a new record for the number of affected individuals at 190 million, with total costs so far reaching 2,457 billion Dollar. The State of Nebraska has now filed a lawsuit against Change Healthcare for operating outdated IT systems that failed to meet enterprise security standards. According to IBM, breaches in the healthcare industry are the most costly, averaging 9.77 million Dollar in 2024.
  • Typhoon Teams Breach 9 US Telecoms: The “Typhoon” suffix is used by Microsoft’s threat actor naming convention for groups with Chinese origins. The Chinese state-sponsored adversary known as Salt Typhoon infiltrated the networks of at least nine major U.S. telecommunications companies, accessing user’s call and text metadata and audio recordings of high-profile government officials. Volt Typhoon breached Singapore Telecommunications (SingTel) and other telecom operators globally. The “Typhoons” exploited vulnerabilities in outdated network devices, including unpatched Microsoft Exchange Server, Cisco routers, Fortinet and Sophos Firewalls and Ivanti VPN appliances. Greenbone is able to detect all known software vulnerabilities associated with Salt Typhoon and Volt Typhoon attacks [1][2].

UK May Ban Ransomware Payments in Public Sector

The UK government’s framework to combat ransomware has proposed a ban on ransom payments by public sector entities and critical infrastructure operators with hopes to deter cyber criminals from targeting them in the first place. However, a new report from The National Audit Office (NAO), the UK’s independent public spending watchdog, says “cyber threat to UK government is severe and advancing quickly”.

The FBI, CISA and NSA all advise against paying ransoms. After all, paying a ransom does not guarantee the recovery of encrypted data or prevent the public release of stolen data, and may even encourage further extortion. On the flip side IBM’s security think-tank acknowledges that many SME organizations could not fiscally survive the downtime imposed by ransomware. While both sides make points here, could enriching cyber criminals while failing to shore-up local talent result in a positive outcome?

Vulnerability in SonicWall SMA 1000 Actively Exploited

Microsoft Threat Intelligence has uncovered active exploitation of SonicWall SMA 1000 gateways via CVE-2025-23006 (CVSS 9.8 Critical). The flaw is caused by improper handling of untrusted data during deserialization [CWE-502]. It could allow an unauthenticated attacker with access to the internal Appliance Management Console (AMC) or Central Management Console (CMC) interface to execute arbitrary OS commands. SonicWall has released hotfix version 12.4.3-02854 to address the flaw.

While no publicly available exploit code has been identified, numerous government agencies have issued alerts including Germany’s BSI CERT-Bund, Canadian Center for Cybersecurity, CISA, and the UK’s NHS (National Health Service). Greenbone is able to detect SonicWall systems impacted by CVE-2025-23006 by remotely checking the version identified from the service banner.

CVE-2024-44243 for Persistent Rootkit in macOS

January 2025 was a firestorm month for Apple security. Microsoft Threat Intelligence has found time to security test macOS, discovering a vulnerability that could allow installed apps to modify the OS System Integrity Protection (SIP). According to Microsoft, this could allow attackers to install rootkits, persistent malware and bypass Transparency, Consent and Control (TCC) which grants granular access permissions to applications on a per-folder basis. While active exploitation has not been reported, Microsoft has released technical details on their findings.

As January closed, a batch of 88 new CVEs, 17 with critical severity CVSS scores were published affecting the full spectrum of Apple products. One of these, CVE-2025-24085, was observed in active attacks and added to CISA’s KEV catalog. On top of these, dual speculative execution vulnerabilities in Apple’s M-series chips dubbed SLAP and FLOP were disclosed but have not yet been assigned CVEs. For SLAP, researchers leveraged chip flaws to exploit Safari WebKit’s heap allocation techniques and manipulated JavaScript string metadata to enable out-of-bounds speculative reads, allowing them to extract sensitive DOM content from other open website tabs. For FLOP, researchers demonstrated that sensitive data can be stolen from Safari and Google Chrome; bypassing Javascript type checking in Safari WebKit and Chrome’s Site Isolation via WebAssembly.

Furthermore, five high severity vulnerabilities were also published affecting Microsoft Office for macOS. Each potentially forfeiting Remote Code Execution (RCE) to an attacker. Affected products include Microsoft Word (CVE-2025-21363), Excel (CVE-2025-21354 and CVE-2025-21362) and OneNote (CVE-2025-21402) for macOS. While no technical details about these vulnerabilities are yet available, all have high CVSS ratings and users should update as soon as possible.

The Greenbone Enterprise Feed includes detection for missing macOS security updates and many other CVEs affecting applications for macOS including the five newly disclosed CVEs in Microsoft Office for Mac.

6 CVEs in Rsync Allow Both Server and Client Takeover

The combination of two newly discovered vulnerabilities may allow the execution of arbitrary code on vulnerable rsyncd servers while having only anonymous read access. CVE-2024-12084, a heap buffer overflow and CVE-2024-12085, an information leak flaw are the culprits. Public mirrors using rsyncd represent the highest risk since they inherently lack access control.

The researchers also found that a weaponized rsync server can read and write arbitrary files on connected clients. This can allow theft of sensitive information and potentially execution of malicious code by modifying executable files.

Here is a summary of the new flaws ordered by CVSS severity:

Collectively, these flaws present serious risk of RCE, data exfiltration and installing persistent malware on both rsyncd servers and unsuspecting clients. Users must update to the patched version, thoroughly look for any Indicators of Compromise (IoC) on any systems that have used rsync, and potentially redeploy file sharing infrastructure. Greenbone is able to detect all known vulnerabilities in rsync and non-compliance with critical security updates.

CVE-2025-0411: 7-Zip Offers MotW Bypass

On January 25, 2025, CVE-2025-0411 (CVSS 7.5 High) was published affecting 7-Zip archiver. The flaw allows bypassing the Windows security feature Mark of the Web (MotW) via specially crafted archive files. MoTW tags files downloaded from the internet with a Zone Identifier alternate data stream (ADS), warning when they originate from an untrusted source. However, 7-Zip versions before 24.09 do not pass the MotW flag to files within nested archives. Exploiting CVE-2025-0411 to gain control of a victim’s system requires human interaction. Targets must open a trojanized archive and then further execute a malicious file contained within.

Interestingly, research from Cofence found government websites around the world have been leveraged for credential phishing, malware delivery and command-and-control (C2) operations via CVE-2024-25608, a Liferay digital platform vulnerability. This flaw allows attackers to redirect users from trusted .gov URLs to malicious phishing sites. Combining redirection from a trusted .gov domain with the 7-Zip flaw has significant potential for stealthy malware distribution.

Considering the risks, users should manually upgrade to version 24.09, which has been available since late 2024. As discussed in the introduction above, software supply chain security often lies in a grey zone, we all depend on software beyond our control. Notably, prior to the publication of CVE-2025-0411, 7-Zip had not alerted users to a security flaw. Furthermore, although 7-Zip is open-source, the product’s GitHub account does not reveal many details or contact information for responsible disclosure.

Furthermore, the CVE has triggered DFN-CERT and BSI CERT-Bund advisories [1][2]. Greenbone is able to detect the presence of vulnerable versions of 7-Zip.

Summary

This edition of our monthly Threat Report reviewed major breaches from 2024 and newly discovered critical vulnerabilities in January 2025. The software supply chain presents elevated risk to all organizations large and small from both open-source and closed-source products. However, open-source software offers transparency and the opportunity for stakeholders to engage proactively in their own security outcomes, either collectively or independently. While cybersecurity costs are significant, advancing technical capabilities will increasingly be a determinant factor in both enterprise and national security. Fortune favors the prepared.

In 2024, geopolitical instability, marked by conflicts in Ukraine and the Middle East, emphasized the need for stronger cybersecurity in both the public and private sector. China targeted U.S. defense, utilities, internet providers and transportation, while Russia launched coordinated cyberattacks on U.S. and European nations, seeking to influence public opinion and create discord among Western allies over the Ukrainian war. As 2024 ends, we can look back at a hectic cybersecurity landscape on the edge.

2024 marked another record setting year for CVE (Common Vulnerabilities and Exposures) disclosures. Even if many are so-called “AI Slop” reports [1][2], the sheer volume of published vulnerabilities creates a big haystack. As IT security teams seek to find high-risk needles in a larger haystack, the chance of oversight becomes more prevalent. 2024 was also a record year for ransomware payouts in terms of volume and size, and Denial of Service (DoS) attacks.

It also saw the NIST NVD outage, which affected many organizations around the world including security providers. Greenbone’s CVE scanner is a CPE (Common Platform Enumeration) matching function and has been affected by the NIST NVD outage. However, Greenbone’s primary scanning engine, OpenVAS Scanner, is unaffected. OpenVAS actively interacts directly with services and applications, allowing Greenbone’s engineers to build reliable vulnerability tests using the details from initial CVE reports.

In 2025, fortune will favor organizations that are prepared. Attackers are weaponizing cyber-intelligence faster; average time-to-exploit (TTE) is mere days, even hours. The rise of AI will create new challenges for cybersecurity. Alongside these advancements, traditional threats remain critical for cloud security and software supply chains. Security analysts predict that fundamental networking devices such as VPN gateways, firewalls and other edge devices will continue to be a hot target in 2025.

In this edition of our monthly Threat Report, we review the most pressing vulnerabilities and active exploitation campaigns that emerged in December 2024.

Mitel MiCollab: Zero-Day to Actively Exploited in a Flash

Once vulnerabilities are published, attackers are jumping on them with increased speed. Some vulnerabilities have public proof of concept (PoC) exploit code within hours, leaving defenders with minimal reaction time. In early December, researchers at GreyNoise observed exploitation of Mitel MiCollab the same day that PoC code was published. Mitel MiCollab combines voice, video, messaging, presence and conferencing into one platform. The new vulnerabilities have drawn alerts from the Belgian national Center for Cybersecurity, the Australian Signals Directorate (ASD) and the UK’s National Health Service (NHS) in addition to the American CISA (Cybersecurity and Infrastructure Security Agency). Patching the recent vulnerabilities in MiCollab is considered urgent.

Here are details about the new actively exploited CVEs in Mitel MiCollab:

  • CVE-2024-41713 (CVSS 7.8 High): A path traversal vulnerability in the NuPoint Unified Messaging (NPM) component of Mitel MiCollab allows unauthenticated path traversal by leveraging the “…/” technique in HTTP requests. Exploitation can expose highly sensitive files.
  • CVE-2024-35286 (CVSS 10 Critical): A SQL injection vulnerability has been identified in the NPM component of Mitel MiCollab which could allow a malicious actor to conduct a SQL injection attack.

Since mid-2022, CISA has tracked three additional actively exploited CVEs in Mitel products which are known to be leveraged in ransomware attacks. Greenbone is able to detect endpoints vulnerable to these high severity CVEs with active checks [4][5].

Array Networks SSL VPNs Exploited by Ransomware

CVE-2023-28461 (CVSS 9.8 Critical) is a Remote Code Execution (RCE) vulnerability in Array Networks Array AG Series and vxAG SSL VPN appliances. The devices, touted by the vendor as a preventative measure against ransomware, are now being actively exploited in recent ransomware attacks. Array Networks themselves were breached by the Dark Angels ransomware gang earlier this year [1][2].

According to recent reports, Array Networks holds a significant market share in the Application Delivery Controller (ADC) market. According to the ​​IDC’s WW Quarterly Ethernet Switch Tracker, they are the market leader in India, with a market share of 34.2%. Array Networks has released patches for affected products running ArrayOS AG 9.4.0.481 and earlier versions. The Greenbone Enterprise Feed has included a detection test for CVE-2023-28461 since it was disclosed in late March 2023.

CVE-2024-11667 in Zyxel Firewalls

CVE-2024-11667 (CVSS 9.8 Critical) in Zyxel firewall appliances are being actively exploited in ongoing ransomware attacks. A directory traversal vulnerability in the web management interface could allow an attacker to download or upload files via a maliciously crafted URL. Zyxel Communications is a Taiwanese company specializing in designing and manufacturing networking devices for businesses, service providers and consumers. Reports put Zyxel’s market share at roughly 4.2% of the ICT industry with a diverse global footprint including large Fortune 500 companies.

A defense in depth approach to cybersecurity is especially important in cases such as this. When attackers compromise a networking device such as a firewall, typically they are not immediately granted access to highly sensitive data. However, initial access allows attackers to monitor network traffic and enumerate the victim’s network in search of high value targets.

Zyxel advises updating your device to the latest firmware, temporarily disabling remote access if updates cannot be applied immediately and applying their best practices for securing distributed networks. CVE-2024-11667 affects Zyxel ATP series firmware versions V5.00 through V5.38, USG FLEX series firmware versions V5.00 through V5.38, USG FLEX 50(W) series firmware versions V5.10 through V5.38 and USG20(W)-VPN series firmware versions V5.10 through V5.38. Greenbone can detect the vulnerability CVE-2024-11667 across all affected products.

Critical Flaws in Apache Struts 2

CVE-2024-53677 (CVSS 9.8 Critical), an unrestricted file upload [CWE-434] flaw affecting Apache Struts 2 allows attackers to upload executable files into web-root directories. If a web-shell is uploaded, the flaw may lead to unauthorized Remote Code Execution. Apache Struts is an open-source Java-based web-application framework widely used by the public and private sectors including government agencies, financial institutions and other large organizations [1]. Proof of concept (PoC) exploit code is publicly available, and CVE-2024-53677 is being actively exploited increasing its risk.

The vulnerability was originally tracked as CVE-2023-50164, published in December 2023 [2][3]. However, similarly to a recent flaw in VMware vCenter, the original patch was ineffective resulting in the re-emergence of vulnerability. CVE-2024-53677 affects the FileUploadInterceptor component and thus, applications not using this module are unaffected. Users should update their Struts2 instance to version 6.4.0 or higher and migrate to the new file upload mechanism. Other new critical CVEs in popular open-source software (OSS) from Apache:

The Apache Software Foundation (ASF) follows a structured process across its projects that encourages private reporting and releasing patches prior to public disclosure so patches are available for all CVEs mentioned above. Greenbone is able to detect systems vulnerable to CVE-2024-53677 and other recently disclosed vulnerabilities in ASF Foundation products.

Palo Alto’s Secure DNS Actively Exploited for DoS

CVE-2024-3393 (CVSS 8.7 High) is a DoS (Denial of Service) vulnerability in the DNS Security feature of PAN-OS. The flaw allows an unauthenticated attacker to reboot PA-Series firewalls, VM-Series firewalls, CN-Series firewalls and Prisma Access devices via malicious packets sent through the data plane. By repeatedly triggering this condition, attackers can cause the firewall to enter maintenance mode. CISA has identified CVE-2024-3393 vulnerability as actively exploited and it’s among five other actively exploited vulnerabilities in Palo Alto’s products over only the past two months.

According to the advisory posted by Palo Alto, only devices with a DNS Security License or Advanced DNS Security License and logging enabled are affected. It would be an easy assumption to say that these conditions mean that top-tier enterprise customers are affected. Greenbone is able to detect the presence of devices affected by CVE-2024-3393 with a version detection test.

Microsoft Security in 2024: Who Left the Windows Open?

While it would be unfair to single out Microsoft for providing vulnerable software in 2024, the Redmond BigTech certainly didn’t beat security expectations. A total of 1,119 CVEs were disclosed in Microsoft products in 2024; 53 achieved critical severity (CVSS > 9.0), 43 were added to CISA’s Known Exploited Vulnerabilities (KEV) catalog, and at least four were known vectors for ransomware attacks. Although the comparison is rough, the Linux kernel saw more (3,148) new CVEs but only three were rated critical severity and only three were added to CISA KEV. Here are the details of the new actively exploited CVEs in Microsoft Windows:

  • CVE-2024-35250 (CVSS 7.8 High): A privilege escalation flaw allowing an attacker with local access to a system to gain system-level privileges. The vulnerability was discovered in April 2024, and PoC exploit code appeared online in October.
  • CVE-2024-49138 (CVSS 7.8 High): A heap-based buffer overflow [CWE-122] privilege escalation vulnerability; this time in the Microsoft Windows Common Log File System (CLFS) driver. Although no publicly available exploit exists, security researchers have evidence that this vulnerability can be exploited by crafting a malicious CLFS log to execute privileged commands at the system privilege level.

Detection and mitigation of these new Windows CVEs is critical since they are actively under attack. Both were patched in Microsoft’s December patch release. Greenbone is able to detect CVE-2024-35250 and CVE-2024-49138 as well as all other Microsoft vulnerabilities published as CVEs.

Summary

2024 highlighted the continuously challenging cybersecurity landscape with record-setting vulnerability disclosures, ransomware payouts, DoS attacks and an alarming rise in active exploitations. The rapid weaponization of vulnerabilities emphasizes the need for a continuous vulnerability management strategy and a defense-in-depth approach.

December saw new critical flaws in Mitel, Apache and Microsoft products. More network products: Array Networks VPNs and Zyxel firewalls are now being exploited by ransomware threat actors underscoring the urgency for proactive patching and robust detection measures. As we enter 2025, fortune will favor those prepared; organizations must stay vigilant to mitigate risks in an increasingly hostile cyber landscape.

An actively exploited RCE (Remote Code Execution) with system privileges vulnerability that does not require user-interaction is as bad as it gets from a technical standpoint. When that CVE impacts software widely used by Fortune 500 companies, it is a ticking time bomb. And when advanced persistent threat actors jump on a software vulnerability such as this, remediation needs to become an emergency response effort. Most recently, CVE-2024-50623 (also now tracked as CVE-2024-55956) affecting more than 4,200 users of Cleo’s MFT (Managed File Transfer) software met all these prerequisites for disaster. It has been implicated in active ransomware campaigns affecting several Fortune 500 companies taking center stage in cybersecurity news.

In this cybersecurity alert, we provide a timeline of events related to CVE-2024-50623 and CVE-2024-55956 and associated ransomware campaigns. Even if you are not using an affected product, this will give you valuable insight into the vulnerability lifecycle and the risks of third-party software supply chains. 

CVE-2024-50623 and CVE-2024-55956: a Timeline of Events

The vulnerability lifecycle is complex. You can review our previous article about next-gen vulnerability management for an in depth explanation on how this process happens. In this report, we will provide a timeline for the disclosure and resolution of CVE-2024-50623 and subsequently CVE-2024-55956 as a failed patch attempt from the software vendor Cleo was uncovered and exploited by ransomware operators. Our Greenbone Enterprise Feed includes detection modules for both CVEs [1][2], allowing organizations to identify vulnerable systems and apply emergency remediation. Here is a timeline of events so far:

  • October 28, 2024: CVE-2024-50623 (CVSS 10 Critical) affecting several Cleo MFT products was published by the vendor and a patched version 5.8.0.21 was
  • November 2024: CVE-2024-50623 was exploited for data exfiltration impacting at least 10 organizations globally including Blue Yonder, a supply chain management service used by Fortune 500 companies.
  • December 3, 2024: Security researchers at Huntress identified active exploitation of CVE-2024-50623 capable of bypassing the original patch (version 5.8.0.21).
  • December 8, 2024: Huntress observed a significant uptick in the rate of exploitation. This could be explained by the exploit code being sold in a Malware as a Service cyber crime business model or simply that the attackers had finished reconnaissance and launched a widespread campaign for maximum impact.
  • December 9, 2024: Active exploitation and proof-of-concept (PoC) exploit code was reported to the software vendor Cleo.
  • December 10, 2024: Cleo released a statement acknowledging the exploitability of their products despite security patches and issued additional mitigation guidance.
  • December 11, 2024: Wachtowr Labs released a detailed technical report describing how CVE-2024-50623 allows RCE via Arbitrary File Write [CWE-434]. Cleo updated their mitigation guidance and released a subsequent patch (version 5.8.0.24).
  • December 13, 2024: A new name, CVE-2024-55956 (CVSS 10 Critical), was issued for tracking this ongoing vulnerability, and CISA added the flaw to its Known Exploited Vulnerabilities (KEV) catalog, flagged for use in ransomware attacks.

Cleo Products Leveraged in Ransomware Attacks

The risk to global business posed by CVE-2024-50623 and CVE-2024-55956 is high. These two CVEs potentially impact more than 4,200 customers of Cleo LexiCom, a desktop-based client for communication with major trading networks, Cleo VLTrader, a server-level solution tailored for mid-enterprise organizations, and Cleo Harmony for large enterprises.

The CVEs have been used as initial access vectors in a recent ransomware campaign. The Termite ransomware operation [1][2] has been implicated in the exploitation of Blue Yonder, a Panasonic subsidiary in November 2024. Blue Yonder is a supply chain management platform used by large tech companies including Microsoft, Lenovo, and Western Digital, and roughly 3,000 other global enterprises across many industries; Bayer, DHL, and 7-Eleven to name a few. Downtime of Blue Yonder’s hosted service caused payroll disruptions for StarBucks. The Clop ransomware group has also claimed responsibility for recent successful ransomware attacks.

In the second stage of some breaches, attackers conducted Active Directory domain enumeration [DS0026], installed web-shells [T1505.003] for persistence [TA0003], and attempted to exfiltrate data [TA0010] from the victim’s network after gaining initial access via RCE. An in-depth technical description of the Termite ransomware’s architecture is also available.

Mitigating CVE-2024-50623 and CVE-2024-55956

Instances of Cleo products version 5.8.0.21 are still vulnerable to cyber attacks. The most recent patch, version 5.8.0.24 is required to mitigate exploitation. All users are urged to apply updates with urgency. Additional mitigation and best practices include disabling the autorun functionality in Cleo products, removing access from the Internet or using firewall rules to restrict access to only authorized IP addresses, and blocking the IP addresses of endpoints implicated in the attacks.

Summary

Cleo Harmony, VLTrader, and LexiCom prior to version 5.8.0.24 are under active exploitation due to critical RCE vulnerabilities (CVE-2024-50623 and CVE-2024-55956). These flaws have been the entry point for successful ransomware attacks against at least 10 organizations and impacting Fortune 500 companies. Greenbone provides detection for affected products and affected users are urged to apply patches and implement mitigation strategies, as attackers will certainly continue to leverage these exploits.

There are health data attractive to attackers in hospitals, doctors’ offices, laboratories and consumers’ devices. The latest security report from the German BSI shows that stealing these data is increasingly becoming a main target of attackers and attacks.

For several years now, the “Network and Information Security Directive“ (NIS) and the KRITIS legislation has required German institutions in eleven sectors to apply stronger and more precise security measures, including reporting obligations, risk analyses and resilience plans. And this is already having its impact on the healthcare sector: according to a recent BSI study, the healthcare sector ranks second in terms of the number of reported data leaks in 2024 – showing clear evidence that now is the time to act.

Almost Every Fifth Incident Report from the Healthcare Sector

Of the 726 reports received by the BSI last year, a quarter came from the transport and traffic sector, while almost 20 % originated in the healthcare sector. Close behind: Energy (18.8 %), Finance and Insurance with 16.5 %, ranking fourth. The threat level is high, especially for hospitals and facilities – even if the reported figures should be treated with caution. Whether banks, for example, are just as motivated to report intrusions and failures as much as hospitals are, seems debatable.

On the other hand, the fact that healthcare data is only ranked eighth in the list of leaked data in the BSI report should not detract from the threat itself. For one thing, the leaked data are sorted according to frequency, and almost every more frequently leaked information also occurs in other contexts (possibly with the exception of social security numbers). However, payment data, names and addresses are information that is likely to be much more attractive to attackers than “naked” health data.

Provisions of the KRITIS Umbrella Law

Meanwhile, the cabinet of the German government launched the KRITIS umbrella law just before the end of the existing coalition. At the beginning of November, the details of the law were agreed, which is intended to act as a kind of protective umbrella over various sectors as an analogous complement to NIS2. It is not yet clear when the Bundestag will pass the law, but chances are high that it will.

According to these plans, the healthcare sector must also introduce operational resilience management, which includes setting up operational risk and crisis management, carrying out risk analyses and assessments, drawing up resilience plans and implementing suitable measures (technical, personnel and organizational) – all measured and organized with the help of Business Continuity Management Systems (BCMS) and Information Security Management Systems (ISMS).

BCMS and ISMS implementations are measured on the basis of maturity levels ( from 1 to 5; the higher, the better). In the BSI report mentioned above, their implementation in the healthcare sector is still mixed, as everywhere. Healthcare institutions are in the middle of the pack, most have implemented ISMS and BCMS, but only a few regularly check them for effectiveness or even improve them.

In the case of the mandatory systems for attack detection, most players have already started implementation and implemented the mandatory (Must) requirements, but only a small proportion have also established target (Should) requirements. Only a few have implemented a continuous improvement process.

Specific Threats in the Healthcare Sector

The same rules and experiences apply to hospitals, doctors’ surgeries and other institutions: For them, the IT security magazine CSO online reports 81 % more ransomware attacks in recent years, with over 91 percent of “malware-related security breaches” in 2024 involving ransomware. According to CSO, only “multi-factor authentication and detection and response technologies”, such as those offered by Greenbone with its vulnerability management, can protect against this. Clouds are not immune to this either: 53 % of administrators in the healthcare sector told CSO that they had “experienced a cloud-related data breach in the last year”. Furthermore, attackers are increasingly targeting websites, botnets, phishing campaigns, and the growing number of vulnerable IoT devices, both in the consumer sector and at the network edge.

October was European Cyber Security Month (ECSM) and International Cybersecurity Awareness month with the latter’s theme being “Secure Our World”. It’s safe to say that instilling best practices for online safety to individuals, businesses and critical infrastructure is mission critical in 2024. At Greenbone, in addition to our Enterprise vulnerability management products, we are happy to make enterprise grade IT security tools more accessible via our free Community Edition, Community Portal and vibrant Community Forum to discuss development, features and get support.

Our core message to cybersecurity decision makers is clear: To patch or not to patch isn’t a question. How to identify vulnerabilities and misconfigurations before an attacker can exploit them is. Being proactive is imperative; once identified, vulnerabilities must be prioritized and fixed. While alerts to active exploitation can support prioritization, waiting to act is unacceptable in high risk scenarios. Key performance indicators can help security teams and executive decision makers track progress quantitatively and highlight areas that need improvement.

In this month’s Threat Tracking blog post, we will review this year’s ransomware landscape including the root causes of ransomware attacks and replay some of the top cyber threats that emerged in October 2024.

International Efforts to Combat Ransomware Continue

The International Counter Ransomware Initiative (CRI), consisting of 68 countries and organizations (notably lacking Russia and China), convened in Washington, D.C., to improve ransomware resilience globally. The CRI aims to reduce global ransomware payments, improve incident reporting frameworks, strengthen partnerships with the cyber insurance industry to lessen the impact of ransomware incidents, and enhance resilience by establishing standards and best practices for both preventing and recovering from ransomware attacks.

Microsoft’s Digital Defense Report 2024 found the rate of attacks has increased so far in 2024, yet fewer breaches are reaching the encryption phase. The result is fewer victims paying ransom overall. Findings from Coveware, Kaseya, and the Chainanalysis blockchain monitoring firm also affirm lower rates of payout. Still, ransomware gangs are seeing record profits; more than 459 million US-Dollar were extorted during the first half of 2024. This year also saw a new single incident high; a 75 million US-Dollar extortion payout amid a trend towards “big game hunting” – targeting large firms rather than small and medium sized enterprises (SMEs).

What Is the Root Cause of Ransomware?

How are successful ransomware attacks succeeding in the first place? Root cause analyses can help: A 2024 Statista survey of organizations worldwide reports exploited software vulnerabilities are the leading root cause of successful ransomware attacks, implicated in 32% of successful attacks. The same survey ranked credential compromise the second-most common cause and malicious email (malspam and phishing attacks) third. Security experts from Symantec claim that exploitation of known vulnerabilities in public facing applications has become the primary initial access vector in ransomware attacks. Likewise, KnowBe4, a security awareness provider, ranked social engineering and unpatched software as the top root causes of ransomware.

These findings bring us back to our core message and highlight the importance of Greenbone’s industry leading core competency: helping defenders identify vulnerabilities lurking in their IT infrastructure so they can fix and close exploitable security gaps.

FortiJump: an Actively Exploited CVE in FortiManager

In late October 2024, Fortinet alerted its customers to a critical severity RCE vulnerability in FortiManager, the company’s flagship network security management solution. Dubbed “FortiJump” and tracked as CVE-2024-47575 (CVSS 9.8), the vulnerability is classified as “Missing Authentication for Critical Function” [CWE-306] in FortiManager’s fgfm daemon. Google’s Mandiant has retroactively searched logs and confirmed this vulnerability has been actively exploited since June 2024 and describes the situation as a mass exploitation scenario.

Another actively exploited vulnerability in Fortinet products, CVE-2024-23113 (CVSS 9.8) was also added to CISA’s KEV catalog during October. This time the culprit is an externally-controlled format string in FortiOS that could allow an attacker to execute unauthorized commands via specially crafted packets.

Greenbone is able to detect devices vulnerable to FortiJump, FortiOS devices susceptible to CVE-2024-23113 [1][2][3], and over 600 other flaws in Fortinet products.

Iranian Cyber Actors Serving Ransomware Threats

The FBI, CISA, NSA and other US and international security agencies issued a joint advisory warning of an ongoing Iranian-backed campaign targeting critical infrastructure networks particularly in healthcare, government, IT, engineering and energy sectors. Associated threat groups are attributed with ransomware attacks that primarily gain initial access by exploiting public facing services [T1190] such as VPNs. Other techniques used in the campaign include brute force attacks [T1110], password spraying [T1110.003], and MFA fatigue attacks.

The campaign is associated with exploitation of the following CVEs:

Greenbone can detect all CVEs referenced in the campaign advisories, providing defenders with visibility and the opportunity to mitigate risk. Furthermore, while not tracked as a CVE, preventing brute force and password spraying attacks is cybersecurity 101. While many authentication services do not natively offer brute force protection, add-on security products can be configured to impose a lockout time after repeated login failures. Greenbone can attest compliance with CIS security controls for Microsoft RDP including those that prevent brute-force and password spraying login attacks.

Finally, according to the EU’s Cyber Resilience Act’s (CRA), Annex I, Part I (2)(d), products with digital elements must “ensure protection from unauthorized access by appropriate control mechanisms”, including systems for authentication, identity and access management, and should also report any instances of unauthorized access. This implies that going forward the EU will eventually require all products to have built-in brute force protection rather than relying on third-party rate limiting tools such as fail2ban for Linux.

Unencrypted Cookies in F5 BIG-IP LTM Actively Exploited

CISA has observed that cyber threat actors are exploiting unencrypted persistent cookies on F5 BIG-IP Local Traffic Manager (LTM) systems. Once stolen, the cookies are used to identify other internal network devices which can further allow passive detection of vulnerabilities within a network. Similar to most web-applications, BIG-IP passes an  HTTP cookie between the client and server to track user sessions. The cookie, by default, is named BIGipServer<pool_name> and its value contains the encoded IP address and port of the destination server.

F5 BIG-IP is a network traffic management suite and LTM is the core module that provides load balancing and traffic distribution across servers. CISA advises organizations to ensure persistent cookies are encrypted. F5 offers guidance for setting up cookie encryption and a diagnostic tool, BIG-IP iHealth to detect unencrypted cookie persistence profiles.

While active exploitation increases the threat to organizations who have not remediated this weakness, the vulnerability has been known since early 2018.  Greenbone has included detection for this weakness since January 2018, allowing users to identify and close the security gap presented by unencrypted cookies in F5 BIG-IP LTM since its disclosure.

New High Risk Vulnerabilities in Palo Alto Expedition

Several new high risk vulnerabilities have been disclosed in Palo Alto’s Expedition, a migration tool designed to streamline the transition from third-party security configurations to Palo Alto’s PAN-OS. While not observed in active campaigns yet, two of the nine total CVEs assigned to Palo Alto in October were rated with EPSS scores in the top 98th percentile.  EPSS (Exploit Prediction Scoring System) is a machine learning prediction model that estimates the likelihood of a CVE being exploited in the wild within 30 days from the model prediction.

Here is a brief technical description of each CVE:

  • CVE-2024-9463 (CVSS 7.5, EPSS 91.34%): An OS command injection vulnerability in Palo Alto’s Expedition allows an unauthenticated attacker to run arbitrary OS commands as root in Expedition, resulting in disclosure of usernames, cleartext passwords, device configurations and device API keys of PAN-OS firewalls.
  • CVE-2024-9465 (CVSS 9.1, EPSS 73.86%): An SQL injection vulnerability in Palo Alto Networks Expedition allows an unauthenticated attacker to reveal sensitive database contents, such as password hashes, usernames, device configurations and device API keys. Once this information has been obtained, attackers can create and read arbitrary files on affected systems.

Four Critical CVEs in Mozilla Firefox: One Actively Exploited

As mentioned before on our Threat Tracking blog, browser security is critical for preventing initial access, especially for workstation devices. In October 2024, seven new critical severity and 19 other less critical vulnerabilities were disclosed in Mozilla Firefox < 131.0 and Thunderbird < 131.0.1. One of these, CVE-2024-9680, was observed being actively exploited against Tor network users and added to CISA’s known exploited catalog. Greenbone includes vulnerability tests to identify all affected Mozilla products.

The seven new critical severity disclosures are:

  • CVE-2024-9680 (CVSS 9.8): Attackers achieved unauthorized RCE in the content process by exploiting a Use-After-Free in Animation timelines. CVE-2024-9680 is being exploited in the wild.
  • CVE-2024-10468 (CVSS 9.8): Potential race conditions in IndexedDB allows memory corruption, leading to a potentially exploitable crash.
  • CVE-2024-9392 (CVSS 9.8): A compromised content process enables arbitrary loading of cross-origin pages.
  • CVE-2024-10467, CVE-2024-9401 and CVE-2024-9402 (CVSS 9.8): Memory safety bugs present in Firefox showed evidence of memory corruption. Security researchers presume that with enough effort some of these could have been exploited to run arbitrary code.
  • CVE-2024-10004 (CVSS 9.1): Opening an external link to an HTTP website when Firefox iOS was previously closed and had an HTTPS tab open could result in the padlock icon showing an HTTPS indicator incorrectly.

Summary

Our monthly Threat Tracking blog covers major cybersecurity trends and high-risk threats. Key insights for October 2024 include expanded efforts to counter ransomware internationally and the role proactive vulnerability management plays in preventing successful ransomware attacks. Other highlights include Fortinet and Palo Alto vulnerabilities actively exploited and updates on an Iranian-backed cyber attack campaign targeting public-facing services of critical infrastructure sector entities. Additionally, F5 BIG-IP LTM’s unencrypted cookie vulnerability, exploited for reconnaissance, and four new Mozilla Firefox vulnerabilities, one actively weaponized, underscore the need for vigilance.

Greenbone facilitates identification and remediation of these vulnerabilities and more, helping organizations enhance resilience against evolving cyber threats. Prioritizing rapid detection and timely patching remains crucial for mitigating risk.

If an organization has high value, you can bet that bad actors are contemplating how to exploit its IT weaknesses for financial gain. Ransomware attacks are the apex threat in this regard, rendering a victim’s data unusable, extorting them for a decryption key. Highly targeted organizations need to understand exactly where their risk lies and ensure that critical assets are exceptionally well protected. However, all organizations with IT infrastructure – even small ones – benefit from assessing their attack surface and mitigating vulnerabilities.

Mass Exploitation attacks are automated campaigns continuously scanning the public Internet looking for easy victims. These campaigns are carried out by bots, executing automated cyber attacks at scale. CloudFlare claims that only 7% of the Internet traffic is malicious bots, while other reports claim malicious bots account for as much as 32% of all Internet activity. Once breached, attackers misuse these compromised assets for malicious activities.

What Happens to Assets Compromised in Mass Exploitation Campaigns?

Once an attacker gains control of a victim’s IT infrastructure, they assess the value of their newly acquired spoils and determine how to best capitalize. The dark web is an underground ecosystem of cybercrime services with its own economy of supply and demand for illicit deeds. Within this ecosystem, Initial Access Brokers (IAB) sell unauthorized access to Ransomware as a Service (RaaS) groups who specialize in ransomware execution; encrypting a victim’s files and extorting them. Mass Exploitation is one way that these IABs gain a foothold.

Compromised assets with lower extortion value may become part of the IAB’s “zombie botnet”; co-opted to continuously scan the Internet for vulnerable systems to compromise. Otherwise, hijacked systems may be used to send malspam and phishing emails, infected with crypto-mining malware, or become an inconspicuous host for command-and-control (C2) infrastructure to support more targeted attack campaigns.

How Mass Exploitation Works

By exploring Mass Exploitation through the lens of the MITRE ATT&CK framework’s tactics, techniques and procedures (TTP) defenders can better understand attacker behavior. If you are not familiar with MITRE ATT&CK, now is a good time to review the MITRE ATT&CK Enterprise Matrix, since it will serve as a reference point for how attackers operate.

Mass exploitation targets large numbers of systems with sophisticated tools that can scan many IP addresses and automatically execute cyber attacks when vulnerabilities are found. These attacks aim to exploit vulnerabilities in software that is commonly exposed to the public Internet, especially software used to host websites and access webservers remotely.

Here’s how Mass Exploitation works:

  • Reconnaissance [TA0043]: Attackers collect sources of vulnerability information such as NIST NVD where CVEs are published with severity scores and reports that include technical details. Attackers also discover sources of exploit code such as exploit-db, GitHub, or other sources such as dark web marketplaces. Alternatively, attackers may develop their own malicious exploits.
  • Weaponization [TA0042]: Attackers build cyber weapons designed to automatically identify and exploit vulnerabilities [T1190] without the need for human interaction.
  • Active Scanning [T1595]: Attackers conduct active scans of the public Internet at scale to discover listening services and their versions [T1595.002]. This process is similar to how cyber defenders conduct vulnerability scans of their own infrastructure, except instead of fixing identified vulnerabilities, attackers plan strategies to exploit them.
  • Attack Deployment and Exploitation: Once an active vulnerability has been found, automated tools attempt to exploit them to control the victim’s system remotely [TA0011] or cause Denial of Service (DoS) [T1499]. A variety of software weaknesses may be involved such as: exploiting default account credentials [CWE-1392], SQL injection [CWE-89], buffer overflows [CWE-119], unauthorized file uploads [CWE-434] or otherwise broken access controls [CWE-284].
  • Assessment and Action on Objectives [TA0040]: Post-compromised, the attacker decides how to best impact the victim for their own gain. Attackers may decide to conduct further reconnaissance, attempting to move laterally to other connected systems in the network [TA0008], steal data from the victim [TA0010], deploy ransomware [T1486] or sell the initial access to other cyber criminals with specialized skills [T1650].

How to Defend Against Mass Exploitation

Defending against Mass Exploitation attacks requires a proactive approach that addresses potential vulnerabilities before they can be exploited. Organizations should adopt fundamental IT security best practices including regular assessments, continuous monitoring, and timely remediation of identified weaknesses.

Here are some key security measures to defend against Mass Exploitation:

  • Build an IT asset inventory: Building a comprehensive inventory of all hardware, software, and network devices within your organization ensures no systems are overlooked during risk and vulnerability assessments and patch management.
  • Conduct a risk assessment: Prioritize assets based on their importance to business operations and determine how preventative efforts should be focused. Regular risk assessments help ensure that the most critical threats are addressed, reducing the chances of a high impact breach.
  • Scan all assets regularly and fix identified vulnerabilities: Perform regular vulnerability scans on all IT assets, especially those exposed to the public internet and with a high risk context. Promptly apply patches or alternative mitigation measures to prevent exploitation. Track and measure vulnerability management progress in a quantified way.
  • Remove unused services and applications: Unused software presents additional attack surface, which may offer attackers an opportunity to exploit vulnerabilities. By minimizing the number of active services and installed applications, potential entry points for attackers are limited.
  • Education and training: Education is important to promote IT security awareness within an organization’s culture. Awareness training also goes a long way towards preventing malspam and phishing attacks from impacting an organization.
  • Employ Anti-Malware solutions: Malware is often distributed through automated malspam and phishing campaigns at scale. Ensure all systems have up-to-date anti-virus software and implement spam filtering to detect and quarantine malicious files.
  • Enforce strong authentication policies: Credential stuffing attacks are often automated components of Mass Exploitation campaigns. By following password best practices, such as using strong randomly generated passwords and not reusing passwords between accounts there is less risk posed by stolen passwords. Implementing password rotation policies, multi-factor authentication (MFA), and using password managers also strengthen password security.
  • Use firewalls and IPS: Firewalls and Intrusion Prevention Systems (IPS) can block malicious traffic by using rules or patterns. Configure rulesets as strictly as possible to block unnecessary inbound traffic from scanning sensitive services. Regularly review and update firewall and IPS configurations to account for current threats.

Summary

Mass Exploitation refers to automated cyber attack campaigns that use bots to scan the public Internet for vulnerable systems. These attacks target a wide range of victims, exploiting known vulnerabilities in software that is commonly exposed to the internet. Once compromised, attackers use the breached systems for various malicious purposes, including launching ransomware attacks, selling access to other criminal groups or further extending botnets. Mass exploitation is a major threat as it allows attackers to operate at scale with minimal effort.

To defend against Mass Exploitation, organizations must implement proactive security measures such as regular vulnerability scanning, timely patch management, strong access controls and network monitoring. Additionally, ensuring that staff have adequate security training can help reduce the risk of becoming a victim of Mass Exploitation campaigns.