CVE-2023-26236
📋 TL;DR
This vulnerability allows local attackers to escalate privileges on Windows systems running WatchGuard EPDR 8.0.21.0002. By sending a specially crafted message to a named pipe, attackers can gain higher privileges than they should have. Only users with local access to affected WatchGuard EPDR installations are impacted.
💻 Affected Systems
- WatchGuard EPDR
📦 What is this software?
Edr Firmware by Watchguard
Epdr Firmware by Watchguard
Epp Firmware by Watchguard
⚠️ Risk & Real-World Impact
Worst Case
An attacker with local access could gain SYSTEM/administrator privileges, enabling complete system compromise, data theft, malware installation, and lateral movement.
Likely Case
Local users or malware with initial foothold could escalate to administrative privileges to disable security controls, persist on the system, or access sensitive data.
If Mitigated
With proper access controls and monitoring, impact is limited to isolated systems with quick detection and containment of privilege escalation attempts.
🎯 Exploit Status
Exploitation requires local access and knowledge of named pipe communication. The vulnerability is in message handling between EPDR processes.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to version after 8.0.21.0002 (check vendor advisory for specific fixed version)
Vendor Advisory: https://www.watchguard.com/wgrd-psirt/advisory/wgsa-2023-00004
Restart Required: Yes
Instructions:
1. Review WatchGuard advisory WGSa-2023-00004. 2. Download and install the latest EPDR version from WatchGuard. 3. Restart affected systems to complete installation.
🔧 Temporary Workarounds
Restrict Named Pipe Access
windowsApply strict access controls to named pipes used by EPDR processes to prevent unauthorized message injection.
Use Windows security policies to restrict access to \\.\pipe\WatchGuard* pipes to only EPDR service accounts
Monitor Named Pipe Activity
windowsImplement monitoring for suspicious named pipe communication attempts targeting EPDR processes.
Configure Windows Event Log monitoring for Event ID 4656 (handle creation) and 4663 (object access) related to WatchGuard named pipes
🧯 If You Can't Patch
- Implement strict principle of least privilege for all user accounts to limit impact of privilege escalation
- Deploy endpoint detection and response (EDR) solutions to detect and block privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check EPDR version in WatchGuard management console or run 'wmic product get name,version' and look for WatchGuard EPDR 8.0.21.0002Check Version:
wmic product where "name like '%WatchGuard EPDR%'" get versionVerify Fix Applied:
Verify EPDR version is updated beyond 8.0.21.0002 and check vendor advisory for confirmation of fix📡 Detection & Monitoring
Log Indicators:
- Unusual named pipe creation/access events (Event ID 4656, 4663) related to WatchGuard processes
- Process creation events showing privilege escalation from non-admin to admin accounts
- EPDR service crashes or unexpected behavior
Network Indicators:
- Local inter-process communication anomalies (not typically network visible)
SIEM Query:
EventID=4656 OR EventID=4663 | where ProcessName contains "WatchGuard" OR ObjectName contains "WatchGuard"