A significant security vulnerability has been identified in WatchGuard’s Fireware OS, potentially exposing over 71,000 devices to remote code execution (RCE) attacks. This flaw, designated as CVE-2025-9242, arises from an out-of-bounds write error within the Internet Key Exchange version 2 (IKEv2) protocol implementation. This vulnerability allows unauthenticated attackers to execute arbitrary code remotely, posing a severe risk to organizations relying on these devices for network security.
Discovery and Scope
The Shadowserver Foundation, a nonprofit organization dedicated to enhancing internet security, conducted extensive scans and reported that as of October 18, 2025, more than 71,000 WatchGuard devices accessible via the internet are running vulnerable versions of Fireware OS. These devices are predominantly located in the United States, with approximately 23,200 instances identified, highlighting the widespread nature of the issue.
Technical Details of the Vulnerability
CVE-2025-9242 is an out-of-bounds write vulnerability found in the IKEv2 implementation of Fireware OS. IKEv2 is a protocol used to establish secure VPN connections. The flaw occurs due to improper bounds checking during the processing of IKEv2 packets, leading to memory corruption. This vulnerability can be exploited remotely over the internet, allowing attackers to gain full control of the affected device and potentially pivot to internal networks.
Affected Devices and Firmware Versions
The vulnerability affects a wide range of WatchGuard’s firewall models, including the Firebox T-series and M-series appliances. Specifically, Fireware OS versions prior to 12.10.3 are susceptible. Despite the release of patches in March 2025, the large number of exposed devices indicates that many organizations have yet to apply these critical updates, leaving their networks vulnerable to potential attacks.
Potential Impact
Exploitation of CVE-2025-9242 could lead to severe consequences, such as unauthorized access to sensitive data, deployment of ransomware, or disruption of network operations. Sectors that heavily rely on WatchGuard hardware, including healthcare and finance, are particularly at risk. The vulnerability has been assigned a CVSS v3.1 base score of 9.8, categorizing it as critical and emphasizing the urgency for remediation.
Recommendations for Mitigation
To mitigate the risks associated with this vulnerability, organizations are strongly advised to:
– Update Fireware OS: Immediately upgrade to Fireware OS version 12.10.3 or later to address the vulnerability.
– Disable IKEv2 if Unnecessary: If IKEv2 is not essential for your operations, consider disabling it to reduce exposure.
– Conduct Network Audits: Utilize tools like Shodan or Shadowserver’s feeds to audit your network perimeter and identify vulnerable devices.
– Monitor for Unusual Activity: Implement continuous monitoring to detect any signs of exploitation or unauthorized access.
Cybersecurity firms such as Rapid7 and Tenable have echoed these recommendations, stressing the importance of proactive measures to safeguard network infrastructure.
Conclusion
The discovery of over 71,000 vulnerable WatchGuard devices underscores the critical need for timely software updates and vigilant network security practices. As cyber threats continue to evolve, maintaining up-to-date defenses is paramount to protecting organizational assets and sensitive information.
