Actively exploited · Published Sep 17, 2025 · Assigned by WatchGuard

CVE-2025-9242WatchGuard Firebox iked Out of Bounds Write Vulnerability

Critical 9.3 Exploited

In plain English

A critical-severity out-of-bounds write in Fireware OS from WatchGuard. Attackers are actively exploiting it in the wild (listed by CISA on November 12, 2025). The chance it is exploited in the next 30 days is estimated at 92.2% (higher than 99.8% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Severity (CVSS 4.0)9.3Critical

Exploit odds (30 days)92.2%top 0.2% of all CVEs

Exploited in the wildYesCISA KEV since Nov 12, 2025

Attack tooling1Public PoC

CISA guidance

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Federal agencies must remediate by Dec 3, 2025.

Official 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.

Affected products (as reported)

Vendor	Product	Versions
WatchGuard	Fireware OS	11.0 – through 11.12.4+54173012.0 – before 12.11.42025.0 – before 2025.1.1
WatchGuard	Fireware OS	12.0 – before 12.3.1+722811
WatchGuard	Fireware OS	12.0 – before 12.5.13

Weakness: CWE-787 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References

https://psirt.watchguard.com/CVE-2025-9242 vendor-advisory
https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00015 vendor-advisory
https://github.com/watchtowrlabs/watchTowr-vs-WatchGuard-CVE-2025-9242/blob/main/watchTowr-vs-WatchGuard-CVE-2025-9242.py exploit
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-9242 government-resource