CVE-2025-12026 Overview
CVE-2025-12026 is an out-of-bounds write vulnerability [CWE-787] in the certificate request command of WatchGuard Fireware OS. The flaw allows an authenticated privileged user to execute arbitrary code through specially crafted Command Line Interface (CLI) commands. The vulnerability affects Fireware OS versions 12.0 through 12.11.4, 12.5 through 12.5.13, and 2025.1 through 2025.1.2, impacting a broad range of WatchGuard Firebox appliances including the T-series, M-series, NV5, FireboxV, and FireboxCloud.
Critical Impact
Successful exploitation grants arbitrary code execution on the firewall appliance, enabling attackers to compromise perimeter security controls and pivot deeper into protected networks.
Affected Products
- WatchGuard Fireware OS 12.0 through 12.11.4
- WatchGuard Fireware OS 12.5 through 12.5.13
- WatchGuard Fireware OS 2025.1 through 2025.1.2
- WatchGuard Firebox T-series, M-series, NV5, FireboxV, and FireboxCloud appliances
Discovery Timeline
- 2025-12-04 - CVE-2025-12026 published to the National Vulnerability Database
- 2025-12-10 - Last updated in NVD database
Technical Details for CVE-2025-12026
Vulnerability Analysis
The vulnerability resides in the certificate request command exposed through the Fireware OS CLI. When processing specially crafted CLI input, the command writes data beyond the bounds of an allocated buffer. This out-of-bounds write [CWE-787] corrupts adjacent memory regions on the appliance.
An attacker who has authenticated to the device with privileged credentials can leverage the memory corruption to redirect execution flow. The result is arbitrary code execution in the context of the affected firewall process. Because Fireware OS is the control plane for WatchGuard Firebox appliances, code execution at this layer compromises perimeter enforcement on the device.
Root Cause
The root cause is insufficient bounds checking on input parameters passed to the certificate request command handler. The handler accepts attacker-controlled data and writes it to a fixed-size buffer without validating length constraints. Standard input validation or safer string-handling primitives would have prevented the overflow condition.
Attack Vector
Exploitation requires network access to the management interface and valid credentials for a privileged administrative account. The attacker invokes the vulnerable certificate request command with crafted arguments through the CLI. No user interaction is required beyond the attacker's own authenticated session. The authenticated privileged user requirement limits the attack surface to insider threats, attackers with compromised admin credentials, or chained exploitation following credential theft.
No public proof-of-concept exploit code is currently available, and the issue is not listed in the CISA Known Exploited Vulnerabilities catalog. See the WatchGuard Security Advisory WGSA-2025-00017 for vendor technical details.
Detection Methods for CVE-2025-12026
Indicators of Compromise
- Unexpected administrative CLI sessions issuing certificate request commands with abnormally long or malformed arguments.
- Crash entries, restarts, or coredumps related to the Fireware OS management process following CLI activity.
- New or unexplained configuration changes, accounts, or outbound connections originating from the Firebox appliance.
Detection Strategies
- Audit Fireware OS administrative logs for invocations of certificate request commands and correlate with the authenticating user, source IP, and session timing.
- Centralize Firebox syslog data in a SIEM or data lake and alert on process crashes coinciding with privileged CLI sessions.
- Monitor for authentication anomalies on privileged Fireware accounts, including impossible-travel logins and off-hours admin access.
Monitoring Recommendations
- Restrict access to the Fireware management interface to a dedicated management VLAN and forward all access logs to a centralized logging platform.
- Enable verbose CLI command auditing on Firebox appliances and retain logs for forensic review.
- Baseline normal certificate management activity so that anomalous certificate request invocations stand out for investigation.
How to Mitigate CVE-2025-12026
Immediate Actions Required
- Upgrade Fireware OS to a fixed release as identified in WatchGuard Security Advisory WGSA-2025-00017.
- Rotate credentials for all privileged Firebox administrative accounts and enforce multi-factor authentication where supported.
- Review recent administrative activity on each Firebox appliance for unauthorized certificate request commands.
Patch Information
WatchGuard has issued fixed releases addressing CVE-2025-12026. Administrators should consult the vendor advisory at WGSA-2025-00017 for the specific fixed versions corresponding to the 12.x and 2025.1 branches and upgrade accordingly. Plan maintenance windows to apply firmware updates to all impacted Firebox appliances, including FireboxV and FireboxCloud instances.
Workarounds
- Limit privileged Fireware OS accounts to the minimum number of administrators required for operations.
- Restrict CLI and management plane access to trusted management hosts using policy-based access controls on the Firebox.
- Disable or remove unused administrator accounts and enforce strong password policies on remaining accounts until patches can be applied.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
