JetBrains TeamCity Authentication Bypass Vulnerability
In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 5 / 5
- KEV catalog (CISA)04 Oct 2023
- Exploited in EUVD (ENISA)04 Oct 2023
- Used by ransomwareyes
- EPSS above 10 %99.99%
- No account, over the networkyes
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Affected products
- 0 <2023.05.4
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
-
Published
-
Exploitation reported (ENISA)
-
Added to the KEV catalog
-
CISA remediation due date
-
EPSS peak: 99.99%
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-63077JetBrains TeamCity Deserialization of Untrusted Data Vulnerability9.7 · Actively exploited
- CVE-2024-27199JetBrains TeamCity Relative Path Traversal Vulnerability8.9 · Background exploitation
- CVE-2024-27198JetBrains TeamCity Authentication Bypass Vulnerability9.9 · Background exploitation