CVE-2025-6018
📋 TL;DR
This CVE-2025-6018 is a Local Privilege Escalation vulnerability in pam-config that allows unprivileged local users (e.g., SSH users) to gain elevated privileges reserved for physically present console users. Attackers can then perform Polkit actions normally restricted to console users, potentially gaining unauthorized system control. Affected systems include Linux distributions using vulnerable PAM configurations.
💻 Affected Systems
- pam-config
- Linux PAM modules
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains full root privileges and complete system control, allowing installation of persistent backdoors, data exfiltration, and lateral movement across the network.
Likely Case
Local user escalates to administrative privileges, modifies system configurations, accesses sensitive data, and performs unauthorized administrative actions.
If Mitigated
With proper access controls and monitoring, impact is limited to isolated privilege escalation that can be detected and contained.
🎯 Exploit Status
Exploitation requires local user access; proof-of-concept details are publicly available in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check specific distribution updates (e.g., Red Hat, SUSE security patches)
Vendor Advisory: https://access.redhat.com/security/cve/CVE-2025-6018
Restart Required: No
Instructions:
1. Check your Linux distribution's security advisory. 2. Update pam-config and related PAM packages using your package manager (yum update, apt-get upgrade, etc.). 3. Verify the update applied successfully.
🔧 Temporary Workarounds
Restrict Polkit allow_active policies
linuxTemporarily modify Polkit policies to restrict allow_active actions until patching is complete.
Review and modify /etc/polkit-1/rules.d/ files to limit allow_active permissions
Limit local user access
linuxRestrict SSH and local login access to trusted users only during vulnerability window.
Modify /etc/ssh/sshd_config to restrict access
Use pam_access to control local logins
🧯 If You Can't Patch
- Implement strict access controls to limit local user privileges and monitor for suspicious activity.
- Deploy additional security monitoring and intrusion detection systems focused on privilege escalation attempts.
🔍 How to Verify
Check if Vulnerable:
Check installed pam-config version against vendor security advisories; examine Polkit configuration for allow_active policies.Check Version:
rpm -q pam-config (Red Hat/SUSE) or dpkg -l | grep pam-config (Debian/Ubuntu)Verify Fix Applied:
Verify pam-config package version matches patched version from vendor advisory; test that local users cannot perform allow_active Polkit actions.📡 Detection & Monitoring
Log Indicators:
- Unusual Polkit authorization requests from non-console users
- Failed or successful privilege escalation attempts in auth logs
- Unexpected user context changes in system logs
Network Indicators:
- N/A - local exploitation only
SIEM Query:
Search for events where user privilege level changes unexpectedly or Polkit actions are performed by non-console users.🔗 References
- https://access.redhat.com/security/cve/CVE-2025-6018
- https://bugzilla.redhat.com/show_bug.cgi?id=2372693
- https://bugzilla.suse.com/show_bug.cgi?id=1243226
- https://cdn2.qualys.com/2025/06/17/suse15-pam-udisks-lpe.txt
- http://www.openwall.com/lists/oss-security/2025/08/28/4
- https://cdn2.qualys.com/2025/06/17/suse15-pam-udisks-lpe.txt
