CVE-2025-52878
📋 TL;DR
This vulnerability in JetBrains TeamCity exposes usernames to users who lack proper permissions to view them. It affects organizations using TeamCity for CI/CD pipelines where user enumeration could reveal internal account structures. The exposure occurs through improper access controls in the web interface.
💻 Affected Systems
- JetBrains TeamCity
📦 What is this software?
Teamcity by Jetbrains
⚠️ Risk & Real-World Impact
Worst Case
Attackers could enumerate all TeamCity usernames, enabling targeted phishing, credential stuffing, or social engineering attacks against identified accounts.
Likely Case
Unauthorized users within the organization could discover usernames of other team members, potentially facilitating internal reconnaissance or privilege escalation attempts.
If Mitigated
With proper network segmentation and access controls, the impact is limited to information disclosure without direct system compromise.
🎯 Exploit Status
Exploitation requires some level of access to the TeamCity interface but no special technical skills.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2025.03.3 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 2025.03.3 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 completed successfully.
🔧 Temporary Workarounds
Restrict Access Controls
allImplement strict network access controls to limit who can reach the TeamCity web interface.
Monitor User Enumeration Attempts
allSet up monitoring for unusual patterns of user listing or enumeration requests in TeamCity logs.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate TeamCity from untrusted networks
- Enable detailed audit logging for all user access and review for enumeration patterns
🔍 How to Verify
Check if Vulnerable:
Check your TeamCity version in the administration interface or via the TeamCity server logs. If version is below 2025.03.3, you are vulnerable.Check Version:
Check the TeamCity web interface under Administration → Server Administration → Server Information, or examine the TeamCity server startup logs.Verify Fix Applied:
After upgrading to 2025.03.3 or later, verify that users without proper permissions cannot view usernames they shouldn't have access to.📡 Detection & Monitoring
Log Indicators:
- Unusual patterns of user listing requests
- Access to user enumeration endpoints by unauthorized accounts
Network Indicators:
- Multiple requests to user-related API endpoints from single sources
SIEM Query:
source="teamcity" AND (event="user_list" OR event="user_query") AND user_role!="admin"