CISA KEV · Known exploitedCritical

CVE-2025-9242

WatchGuard Firebox

An Out-of-bounds Write vulnerability in WatchGuard Fireware OS 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.This vulnerability affects Fireware OS 11.10.2 up to and including 11.12.4_Update1, 12.0 up to and including 12.11.3 and 2025.1.

CVSS: 9.3
EPSS: 91.1%
CISA KEV: Listed
Published: 2025.09.17

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability91.1%

Technical severityCVSS 9.3

Vulnerability overview

Affected product and versions

Product: WatchGuard Firebox
Affected versions: 12.0, 11.10.2, 2025.0, >= 11.10.2 < 12.11.4, >= 11.10.2 < 12.5.13, 2025.1
Fixed versions: 12.11.4, 12.5.13

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA 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.

Due date: 2025.12.03

1
Identify
Confirm that WatchGuard Firebox and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS 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/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
CWE: CWE-787
KEV added: 2025.11.12
Ransomware use: 미확인