CVE-2013-4561
📋 TL;DR
CVE-2013-4561 is a temporary file handling vulnerability in OpenShift's mcollective facts update cron job that allows local attackers to overwrite arbitrary files. This affects OpenShift Origin and Enterprise deployments where the vulnerable cron job is running. Successful exploitation could lead to privilege escalation or data manipulation.
💻 Affected Systems
- OpenShift Origin
- OpenShift Enterprise
📦 What is this software?
Openshift by Redhat
⚠️ Risk & Real-World Impact
Worst Case
Local attacker gains root privileges by overwriting critical system files, leading to complete system compromise and data exfiltration.
Likely Case
Local user escalates privileges to gain unauthorized access to sensitive configuration files or modifies application data.
If Mitigated
Attack limited to user's own files or prevented entirely through proper file permissions and isolation.
🎯 Exploit Status
Exploitation requires local shell access to the OpenShift node and knowledge of the vulnerable temporary file location.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit f1abe972794e35a4bfba597694ce829990f14d39 and later
Vendor Advisory: https://bugzilla.redhat.com/show_bug.cgi?id=1029652
Restart Required: No
Instructions:
1. Update OpenShift to version containing commit f1abe972794e35a4bfba597694ce829990f14d39
2. Apply the patch that fixes temporary file handling in the mcollective facts update script
3. Verify the cron job uses secure temporary file creation methods
🔧 Temporary Workarounds
Disable vulnerable cron job
linuxTemporarily disable the mcollective facts update cron job until patching is possible
crontab -e
Comment out or remove the mcollective facts update line
Secure temporary directory permissions
linuxSet restrictive permissions on temporary directories used by the cron job
chmod 700 /tmp/openshift-mcollective-facts
chown root:root /tmp/openshift-mcollective-facts
🧯 If You Can't Patch
- Implement strict access controls to limit who has shell access to OpenShift nodes
- Monitor file system changes in temporary directories used by OpenShift cron jobs
🔍 How to Verify
Check if Vulnerable:
Check if OpenShift version predates commit f1abe972794e35a4bfba597694ce829990f14d39 and if the mcollective facts update cron job exists in crontabCheck Version:
openshift version | grep -i openshiftVerify Fix Applied:
Verify the OpenShift version includes the fix commit and inspect the mcollective facts update script for secure temporary file handling📡 Detection & Monitoring
Log Indicators:
- Unusual file modifications in /tmp directories
- Cron job execution errors related to mcollective facts
Network Indicators:
- None - local exploitation only
SIEM Query:
source="cron" AND "mcollective" AND ("error" OR "permission denied")