CVE-2024-56349
📋 TL;DR
This vulnerability in JetBrains TeamCity allows unauthorized users to modify build logs due to improper access control. It affects organizations using TeamCity for CI/CD pipelines where unauthorized users could tamper with build artifacts. The impact is limited to log modification rather than code execution.
💻 Affected Systems
- JetBrains TeamCity
📦 What is this software?
Teamcity by Jetbrains
⚠️ Risk & Real-World Impact
Worst Case
Attackers could modify build logs to hide malicious activity, obscure security incidents, or manipulate audit trails, potentially enabling supply chain attacks if logs are used for compliance verification.
Likely Case
Unauthorized internal users or compromised accounts could tamper with build logs to hide errors, manipulate build status reporting, or interfere with debugging processes.
If Mitigated
With proper access controls and monitoring, impact is limited to log integrity issues that can be detected through log verification mechanisms.
🎯 Exploit Status
Exploitation requires some level of access to the TeamCity instance but not administrative privileges. The vulnerability is in access control logic, making exploitation straightforward once initial access is obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2024.12 or later
Vendor Advisory: https://www.jetbrains.com/privacy-security/issues-fixed/
Restart Required: Yes
Instructions:
1. Backup your TeamCity configuration and data. 2. Download TeamCity 2024.12 or later from the JetBrains website. 3. Stop the TeamCity service. 4. Install the new version following JetBrains upgrade documentation. 5. Restart the TeamCity service. 6. Verify the upgrade was successful.
🔧 Temporary Workarounds
Restrict Access to Build Logs
allImplement additional access controls and monitoring for build log access and modification.
# Configure TeamCity project roles to restrict 'View build log' and 'Edit build log' permissions
# Review and tighten user permissions in Administration -> Users & Groups
Enable Audit Logging
allEnable comprehensive audit logging to detect unauthorized log modification attempts.
# In TeamCity, enable audit logging in Administration -> Audit
# Configure log retention and monitoring for audit events
🧯 If You Can't Patch
- Implement strict access controls and principle of least privilege for all TeamCity users
- Enable and regularly review audit logs for unauthorized log modification attempts
🔍 How to Verify
Check if Vulnerable:
Check TeamCity version in Administration -> Server Administration -> Server Configuration. If version is below 2024.12, the system is vulnerable.Check Version:
# On TeamCity server, check version via: cat $TEAMCITY_HOME/buildAgent/logs/teamcity-server.log | grep 'TeamCity' | head -1Verify Fix Applied:
After upgrading, verify version is 2024.12 or higher in Administration -> Server Administration -> Server Configuration. Test that unauthorized users cannot modify build logs.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to build logs
- Unexpected modifications to build logs
- Failed permission checks in audit logs
Network Indicators:
- Unusual API calls to build log endpoints from unauthorized users
SIEM Query:
source="teamcity" AND (event_type="log_modification" OR event_type="permission_violation") AND user_role!="admin"