CVE-2025-9242
WatchGuard Firebox iked Out of Bounds Write Vulnerability
- Published
- Updated
- Reserved
- Assigned by
- WatchGuard
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as WatchGuard Firebox Out-of-Bounds Write Vulnerability.
- Added
- 12 Nov 2025
- Fix due (US federal)
- 3 Dec 2025
- Used by ransomware
- Not known
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| WatchGuardCNA (assigner) | 4.0 | Critical9.3 | 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 |
| NVDNVD · Analyzed | 4.0 | Critical9.3 | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 92.2% · top 0.2% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.3.
Weakness
Affected products
- affected 11.0 – ≤ 11.12.4+541730
- affected 12.0 – < 12.11.4
- affected 2025.0 – < 2025.1.1
- affected 12.0 – < 12.3.1+722811
- affected 12.0 – < 12.5.13
What to do
Solution: Fireware OS 2025.1.1, Fireware OS 12.11.4, Fireware OS 12.5.13, Fireware OS 12.3.1+722811
Workaround: If your Firebox is only configured with Branch Office VPN tunnels to static gateway peers and you are not able to immediately upgrade the device to a version of Fireware OS with the vulnerability resolution, you can follow WatchGuard’s recommendations for Secure Access to Branch Office VPNs that Use IPSec and IKEv2 as a temporary workaround.
Exploitation: We have evidence that suggests this vulnerability is under active exploitation. Indicators of Attack We are providing the following Indicators of Attack (IoAs) to help device owners identify potential attempts to exploit this vulnerability against vulnerable Firebox appliances. These IoAs are only applicable on devices that lack the resolution described later in this advisory. Abnormally large IKE_AUTH request IDi payload With iked diagnostic logging set to the Info logging level, the iked process generates a log message when the Firebox receives an IKE_AUTH request message. An IKE_AUTH request log message with an abnormally large IDi payload size (greater than 100 bytes) is a strong indicator of an attack. The following example diagnostic log shows an example IDi payload size of 300 bytes. 1970-01-01 01:00:00 iked (203.0.113.1<->203.0.113.2)"IKE_AUTH request" message has 6 payloads [ IDi(sz=300) CERT(sz=889) SA(sz=44) TSi(sz=24) TSr(sz=24) N(sz=8)] IKE Process Hang During a successful exploit, the IKED process (responsible for handling IKE negotiations) will hang, interrupting VPN tunnel negotiations and re-keys. This is a strong indicator of attack. Existing tunnels may continue to pass traffic. IKED Process Crash After a failed or successful exploit, the IKED process will crash and generate a fault report on the Firebox. Be aware, there are other situations that could cause the IKED process to crash. This is a weak indicator of attack.
References (4)
- https://psirt.watchguard.com/CVE-2025-9242 (opens in a new tab)vendor-advisory
- https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2025-00015 (opens in a new tab)vendor-advisory
- https://github.com/watchtowrlabs/watchTowr-vs-WatchGuard-CVE-2025-9242/blob/main/watchTowr-vs-WatchGuard-CVE-2025-9242.py (opens in a new tab)exploit
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-9242 (opens in a new tab)government-resource
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2025-9242)Record last updated .