CVE-2025-9242
CVE-2025-9242 is a security flaw in WatchGuard Firebox. Attackers can run their own code on WatchGuard Firebox from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 12 Nov 2025.[1]
WatchGuard Firebox is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fixed in version 12.11.4, 2025.1.1, 12.3.1+722811 and 12.5.13 of Fireware OS.
Description
CISA calls it an out-of-bounds write in WatchGuard Firebox. In its words: “WatchGuard Firebox contains an out-of-bounds write vulnerability in the OS iked process that may allow a remote unauthenticated attacker to execute arbitrary code.”[1]
The CVE record adds: “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.”[2]
The underlying weakness is out-of-bounds write (CWE-787), in MITRE’s list of common software weaknesses.
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| Fireware OS | 12.11.4 |
| Fireware OS | 2025.1.1 |
| Fireware OS | 12.3.1+722811 |
| Fireware OS | 12.5.13 |
Most families won’t have WatchGuard Firebox; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 12 Nov 2025, 56 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 3 Dec 2025 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 92%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
WatchGuard has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.WatchGuard Firebox is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed (fixed in version 12.11.4, 2025.1.1, 12.3.1+722811 and 12.5.13 of Fireware OS), or not in use. CISA gave US government agencies until 3 Dec 2025 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 92%.[4] |
See also
Other WatchGuard Firebox flaws
- CVE-2025-14733: out of bounds write ·
Other WatchGuard flaws
- CVE-2022-23176, WatchGuard Firebox and XTM: privilege escalation ·
- CVE-2022-26318, WatchGuard Firebox and XTM Appliances: arbitrary code execution ·
Other out-of-bounds write flaws
- CVE-2026-86950, Apple devices: out-of-bounds write ·
- CVE-2026-53266, Linux Kernel: out-of-bounds write ·
- CVE-2026-87491, Chrome and other Chromium browsers: out of bounds write ·
- CVE-2026-53362, Linux Kernel: unspecified ·
- CVE-2022-0995, Linux Kernel: out-of-bounds write ·
Added the same day
- CVE-2025-62215, Microsoft Windows: race condition ·
- CVE-2025-12480, Gladinet Triofox: improper access control ·
Every WatchGuard flaw on CISA’s list · Everything added in November 2025
References
- ^ Cybersecurity and Infrastructure Security Agency. “WatchGuard Firebox Out-of-Bounds Write Vulnerability”. Known Exploited Vulnerabilities Catalog, added 12 Nov 2025.
- ^ National Institute of Standards and Technology. “CVE-2025-9242 Detail”. National Vulnerability Database, published 17 Sep 2025.
- ^ WatchGuard. Advisories and fixes: watchguard.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.922, percentile 99.8, 31 Oct 2026.
- CVE Program. “CVE-2025-9242”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.