Full Report
WatchGuard security advisory (AV26-189)
Analysis Summary
# Vulnerability: Multiple Vulnerabilities in WatchGuard Firebox (Fireware OS)
## CVE Details
*Note: This summary covers multiple CVEs identified in the advisory.*
**1. CVE-2026-3342**
- CVE ID: CVE-2026-3342
- CVSS Score: High/Critical (Score not explicitly listed in bulletin, but categorized as "Out of Bounds Write")
- CWE: CWE-787 (Out-of-bounds Write)
**2. CVE-2026-3343**
- CVE ID: CVE-2026-3343
- CVSS Score: Medium
- CWE: CWE-79 (Reflected Cross-Site Scripting)
**3. CVE-2026-3344**
- CVE ID: CVE-2026-3344
- CVSS Score: Medium/High
- CWE: CWE-290 (Authentication Bypass / Integrity Check Bypass)
## Affected Systems
- **Products:** WatchGuard Firebox devices running Fireware OS
- **Versions:**
- Versions prior to 11.12.4_Update1
- Versions prior to 12.5.17
- Versions prior to 12.11.8
- Versions prior to 2026.1.2
- **Configurations:** Systems with the Fireware Web UI enabled are specifically targeted by the XSS vulnerability (CVE-2026-3343).
## Vulnerability Description
WatchGuard has addressed three distinct security flaws:
1. **Out-of-Bounds Write (CVE-2026-3342):** A memory corruption flaw that occurs when the system writes data beyond the end of the intended buffer. This can lead to system crashes or arbitrary code execution.
2. **Reflected XSS (CVE-2026-3343):** Improper neutralization of user-supplied input in the Fireware Web UI allows an attacker to inject malicious scripts into a victim's browser session.
3. **Integrity Check Bypass (CVE-2026-3344):** A flaw in the system's verification process that allows an attacker to bypass legitimate security checks intended to ensure the integrity of the system firmware or configuration.
## Exploitation
- **Status:** Not explicitly reported as exploited in the wild (based on provided summary).
- **Complexity:** Low to Medium
- **Attack Vector:** Network (Remote)
## Impact
- **Confidentiality:** Moderate to High (Potential for session hijacking via XSS or data access via memory corruption).
- **Integrity:** High (Ability to bypass system checks and modify system behavior).
- **Availability:** High (Out-of-bounds write can lead to complete system denial of service).
## Remediation
### Patches
WatchGuard recommends upgrading to the following versions or later:
- Fireware OS 11.12.4_Update1
- Fireware OS 12.5.17
- Fireware OS 12.11.8
- Fireware OS 2026.1.2
### Workarounds
- **Restrict Management Access:** Limit access to the Fireware Web UI to trusted internal IP addresses only.
- **VPN Requirement:** Ensure all administrative access to the Firebox is conducted through a secure VPN tunnel rather than exposing the management interface to the public internet.
## Detection
- **Indicators of Compromise:** Unusual administrative logins, unexpected system reboots (crashes), or unauthorized configuration changes.
- **Detection Methods:** Monitor web server logs for the Fireware Web UI for suspicious scripts or abnormal URL parameters. Audit integrity logs for bypass events.
## References
- WatchGuard Firebox Out of Bounds Write: hxxps[://]www[.]watchguard[.]com/wgrd-psirt/advisory/wgsa-2026-00003
- WatchGuard Firebox Reflected XSS: hxxps[://]www[.]watchguard[.]com/wgrd-psirt/advisory/wgsa-2026-00004
- WatchGuard Firebox Integrity Check Bypass: hxxps[://]www[.]watchguard[.]com/wgrd-psirt/advisory/wgsa-2026-00005
- WatchGuard Security Advisories Main Page: hxxps[://]www[.]watchguard[.]com/wgrd-psirt/advisories