CVE-2025-67738
📋 TL;DR
This vulnerability in Webmin's Squid module allows authenticated users with Cache Manager permissions to execute arbitrary commands on the server through improper argument quoting in cachemgr.cgi. It affects Webmin installations with the Squid module enabled and Cache Manager feature available. Attackers need valid Webmin credentials and specific permissions to exploit this.
💻 Affected Systems
- Webmin
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Authenticated attacker gains remote code execution with privileges of the Webmin process, potentially leading to full system compromise, data theft, or lateral movement.
Likely Case
Privileged authenticated user escalates privileges to execute arbitrary commands on the underlying operating system.
If Mitigated
With proper access controls limiting Cache Manager permissions, impact is reduced to authorized users only.
🎯 Exploit Status
Exploitation requires authenticated access to Webmin with specific Cache Manager permissions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.600 and later
Vendor Advisory: https://webmin.com/security/#privilige-escalation-using-squid-module-cve-2025-67738
Restart Required: No
Instructions:
1. Backup Webmin configuration. 2. Update Webmin to version 2.600 or later via package manager or manual installation. 3. Verify update completed successfully.
🔧 Temporary Workarounds
Disable Squid Cache Manager
allRemove or restrict Cache Manager permissions for all users
Edit Webmin user permissions to remove 'cms' security option
Disable Squid Module
allTemporarily disable the Squid module if not required
Navigate to Webmin → Webmin Configuration → Modules → Uncheck Squid module
🧯 If You Can't Patch
- Implement strict access controls limiting Cache Manager permissions to trusted administrators only
- Monitor Webmin logs for suspicious activity and implement network segmentation
🔍 How to Verify
Check if Vulnerable:
Check Webmin version via web interface or command line. If version is below 2.600 and Squid module is enabled, system is vulnerable.Check Version:
cat /etc/webmin/version or check via Webmin web interfaceVerify Fix Applied:
Verify Webmin version is 2.600 or higher and test Cache Manager functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution patterns in Webmin logs
- Multiple failed authentication attempts followed by Cache Manager access
Network Indicators:
- Unusual outbound connections from Webmin server
- Suspicious payloads in Webmin traffic
SIEM Query:
source="webmin.log" AND ("cachemgr.cgi" OR "squid") AND command_execution_patterns