CVE-2025-9242
WatchGuard Firebox Out-of-Bounds Write Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 3 December 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
An Out-of-bounds Write vulnerability in the WatchGuard Fireware OS iked process may allow a remote unauthenticated attacker to execute arbitrary code. This vulnerability affects both the mobile user VPN with IKEv2 and the branch office VPN using IKEv2 when configured with a dynamic gateway peer. If the Firebox was previously configured with the mobile user VPN with IKEv2 or a branch office VPN using IKEv2 to a dynamic gateway peer, and both of those configurations have since been deleted, that Firebox may still be vulnerable if a branch office VPN to a static gateway peer is still configured.
- CVSS 4.0
- 9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 92.22% probability · 100th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Listed 12 November 2025 · due 3 December 2025
- Weakness
- CWE-787
- Affected
- watchguard/fireware
- Source
- 5d1c2695-1a31-4499-88ae-e847036fd7e3
EPSS 92.2% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00015 ; https://nvd.nist.gov/vuln/detail/CVE-2025-9242
References
- https://psirt.watchguard.com/CVE-2025-9242Broken Link
- https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00015Vendor Advisory
- https://github.com/watchtowrlabs/watchTowr-vs-WatchGuard-CVE-2025-9242/blob/main/watchTowr-vs-WatchGuard-CVE-2025-9242.pyExploit
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-9242US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.