CVE-2024-47533
📋 TL;DR
Cobbler versions 3.0.0 through 3.2.2 and 3.3.0 through 3.3.6 have an authentication bypass vulnerability where the get_shared_secret() function always returns '-1'. This allows any network-connected attacker to authenticate as an empty user with password '-1' and gain full administrative control of the Cobbler server. Organizations running vulnerable Cobbler installations for Linux deployment automation are affected.
💻 Affected Systems
- Cobbler
⚠️ 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
Complete compromise of the Cobbler server allowing attackers to modify system images, inject malicious code into deployed systems, reconfigure network settings, and potentially pivot to other infrastructure.
Likely Case
Unauthorized users gaining administrative access to modify deployment configurations, inject backdoors into system images, or disrupt provisioning operations.
If Mitigated
Limited impact if Cobbler is isolated in a restricted network segment with strict access controls and monitoring.
🎯 Exploit Status
The exploit is trivial - simply connect to XML-RPC interface with empty username and '-1' password. Public proof-of-concept exists in the advisory and commit references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 3.2.3 or 3.3.7
Vendor Advisory: https://github.com/cobbler/cobbler/security/advisories/GHSA-m26c-fcgh-cp6h
Restart Required: Yes
Instructions:
1. Backup current Cobbler configuration. 2. Update Cobbler using package manager: 'sudo apt update && sudo apt upgrade cobbler' or 'sudo yum update cobbler'. 3. Verify version with 'cobbler version'. 4. Restart Cobbler service: 'sudo systemctl restart cobblerd'. 5. Test authentication functionality.
🔧 Temporary Workarounds
Network Isolation
linuxRestrict network access to Cobbler server to only trusted management systems
sudo iptables -A INPUT -p tcp --dport 25151 -s TRUSTED_IP -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 25151 -j DROP
Disable XML-RPC Interface
linuxTemporarily disable the vulnerable XML-RPC interface if not required
sudo systemctl stop cobblerd
Comment out XML-RPC configuration in /etc/cobbler/settings
🧯 If You Can't Patch
- Immediately restrict network access to Cobbler server using firewall rules to only allow connections from trusted management systems
- Implement network monitoring for unauthorized access attempts to Cobbler's XML-RPC interface (port 25151 by default)
🔍 How to Verify
Check if Vulnerable:
Check Cobbler version: 'cobbler version' or 'rpm -q cobbler' or 'dpkg -l cobbler'. If version is between 3.0.0-3.2.2 or 3.3.0-3.3.6, system is vulnerable.Check Version:
cobbler versionVerify Fix Applied:
After patching, verify version is 3.2.3 or higher, or 3.3.7 or higher. Test authentication by attempting to connect with invalid credentials should fail.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts with empty username
- Successful authentication with username ''
- Unusual configuration changes from unexpected sources
- XML-RPC access from unauthorized IP addresses
Network Indicators:
- XML-RPC traffic to Cobbler port (default 25151) from unexpected sources
- Authentication attempts with empty credentials
SIEM Query:
source="cobbler.log" AND (username="" OR auth_failure OR "shared_secret")