CVE-2019-20327
📋 TL;DR
CVE-2019-20327 is a privilege escalation vulnerability in Centreon monitoring software where the cwrapper_perl setuid executable has insecure permissions, allowing local attackers to execute arbitrary Perl scripts with root privileges. This affects Centreon Infrastructure Monitoring Software through version 19.10. Any system running vulnerable Centreon versions with local user access is at risk.
💻 Affected Systems
- Centreon Infrastructure Monitoring Software
📦 What is this software?
Centreon by Centreon
⚠️ Risk & Real-World Impact
Worst Case
Local attacker gains full root privileges on the Centreon server, enabling complete system compromise, data theft, lateral movement, and persistence.
Likely Case
Local user or compromised service account escalates to root to install backdoors, steal credentials, or disrupt monitoring services.
If Mitigated
With proper access controls limiting local user accounts, impact is reduced to authorized users only, but still represents significant risk.
🎯 Exploit Status
Exploitation requires local access but is straightforward once access is obtained. Public proof-of-concept demonstrates privilege escalation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 19.10.1 and later
Vendor Advisory: https://www.centreon.com/en/
Restart Required: No
Instructions:
1. Update Centreon to version 19.10.1 or later. 2. Follow Centreon upgrade documentation. 3. Verify cwrapper_perl permissions are corrected.
🔧 Temporary Workarounds
Remove setuid bit from cwrapper_perl
linuxRemove the setuid permission from the vulnerable executable to prevent privilege escalation.
chmod u-s /usr/share/centreon/www/modules/centreon-awie/cwrapper_perl
Restrict file permissions
linuxSet strict permissions on cwrapper_perl to prevent unauthorized execution.
chmod 700 /usr/share/centreon/www/modules/centreon-awie/cwrapper_perl
🧯 If You Can't Patch
- Implement strict access controls to limit local user accounts on Centreon servers
- Monitor for suspicious privilege escalation attempts and unauthorized root access
🔍 How to Verify
Check if Vulnerable:
Check if cwrapper_perl has setuid bit set: ls -la /usr/share/centreon/www/modules/centreon-awie/cwrapper_perl | grep '^-..s'Check Version:
centreon -v or check Centreon web interface versionVerify Fix Applied:
Verify setuid bit is removed: ls -la /usr/share/centreon/www/modules/centreon-awie/cwrapper_perl should not show 's' in permissions📡 Detection & Monitoring
Log Indicators:
- Unusual privilege escalation events
- Execution of cwrapper_perl by non-root users
- Sudden root access from non-privileged accounts
Network Indicators:
- None - this is local exploitation only
SIEM Query:
process.name='cwrapper_perl' AND user.name!='root'