CVE-2011-3618
📋 TL;DR
CVE-2011-3618 is a symlink attack vulnerability in the atop system monitoring tool due to insecure temporary file handling. Attackers can exploit this to overwrite arbitrary files on the system, potentially leading to privilege escalation or data corruption. Systems running vulnerable versions of atop with the tool executed by privileged users are affected.
💻 Affected Systems
- atop
📦 What is this software?
Atop by Atop Project
⚠️ Risk & Real-World Impact
Worst Case
Privilege escalation to root, complete system compromise, or persistent backdoor installation through arbitrary file overwrites.
Likely Case
Local privilege escalation allowing attackers to gain elevated privileges on the system.
If Mitigated
Limited impact with proper file permissions and SELinux/apparmor restrictions in place.
🎯 Exploit Status
Exploitation requires local access and knowledge of temporary file creation patterns. Symlink attacks are well-understood exploitation techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: atop-1.27-7 for RHEL/CentOS, atop-1.26-2 for Debian/Ubuntu
Vendor Advisory: https://access.redhat.com/security/cve/cve-2011-3618
Restart Required: No
Instructions:
1. Update via package manager: 'yum update atop' (RHEL/CentOS) or 'apt-get update && apt-get upgrade atop' (Debian/Ubuntu). 2. Verify the updated version with 'atop -V'.
🔧 Temporary Workarounds
Disable atop execution
linuxTemporarily disable atop cron jobs or remove execution privileges
chmod -x /usr/bin/atop
systemctl stop atop.service
crontab -e # comment out atop entries
Use secure temporary directory
linuxConfigure atop to use secure temporary directory with proper permissions
mkdir -p /var/run/atop
chmod 700 /var/run/atop
export TMPDIR=/var/run/atop
🧯 If You Can't Patch
- Restrict atop execution to trusted users only and monitor for unauthorized access
- Implement mandatory access controls (SELinux/apparmor) to limit atop's file access capabilities
🔍 How to Verify
Check if Vulnerable:
Check atop version: 'rpm -q atop' (RHEL/CentOS) or 'dpkg -l | grep atop' (Debian/Ubuntu). If version is older than patched versions listed above, system is vulnerable.Check Version:
atop -V 2>/dev/null || rpm -q atop || dpkg -l | grep atopVerify Fix Applied:
Verify updated version and check that temporary files are created securely (look for use of mkstemp or similar secure functions).📡 Detection & Monitoring
Log Indicators:
- Unusual file creation in /tmp directories by atop process
- Symlink creation attempts in temporary directories
- Failed privilege escalation attempts in system logs
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
process.name:"atop" AND file.path:"/tmp/*" AND file.action:"create"🔗 References
- https://access.redhat.com/security/cve/cve-2011-3618
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-3618
- https://security-tracker.debian.org/tracker/CVE-2011-3618
- https://access.redhat.com/security/cve/cve-2011-3618
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-3618
- https://security-tracker.debian.org/tracker/CVE-2011-3618
