# CVE-2023-42793: JetBrains TeamCity - Authentication Bypass

> Live exploitation tracking for CVE-2023-42793 by the CrowdSec Live Exploit Tracker, built from real-world attack data crowdsourced from CrowdSec's global network.

Page: https://tracker.crowdsec.net/cves/CVE-2023-42793

## Key facts

- **Exploitation phase:** Background Noise. Continuous low-level scanning or exploitation attempts are observed, mostly opportunistic and automated.
- **CVSS score:** 9.8
- **Public exploit available:** Yes
- **Affected products:** JetBrains TeamCity
- **Weaknesses:** CWE-288 (Authentication Bypass Using an Alternate Path or Channel); CWE-306 (Missing Authentication for Critical Function)
- **Tags:** cicd

## Description

In JetBrains TeamCity before 2023.05.4 authentication bypass leading to RCE on TeamCity Server was possible

## CrowdSec analysis

[CVE-2023-42793](https://euvd.enisa.europa.eu/vulnerability/CVE-2023-42793) is a critical vulnerability in JetBrains TeamCity, where an authentication bypass can enable remote code execution on the TeamCity server.

CrowdSec has been tracking this vulnerability and its exploits since 15th of December 2023.

Insights from the CrowdSec network reveal that the attackers trying to exploit CVE-2023-42793 are composed of a fairly even mix of opportunistic and targeted actors. Some attackers employ preliminary reconnaissance, while others use indiscriminate scanning.
In addition, according to the CrowdSec network, attack volume against CVE-2023-42793 has dipped slightly compared to the previous week. Although still commonly targeted, the decline suggests a cooling-off period. Long-term relevance remains, but attention is waning.

Attack attempts aim to exploit weaknesses in the TeamCity authentication process, usually by targeting exposed server endpoints in tailored campaigns.

## Timeline

- 2023-09-19: CVE Published. CVE-2023-42793 is published to NVD.
- 2023-10-04: CISA KEV. CVE-2023-42793 is added to the Known Exploited Vulnerabilities catalog by CISA.
- 2023-10-25: CISA Remediation Deadline. Expiration of the CISA remediation deadline as described in [BOD 22-01](https://www.cisa.gov/news-events/directives/bod-22-01-reducing-significant-risk-known-exploited-vulnerabilities).
- 2023-12-15: Rule Released. CrowdSec releases a rule to detect CVE-2023-42793 exploitation attempts against the CrowdSec Network.
- 2024-11-23: CrowdSec First Seen. CrowdSec observes in-the-wild exploitation of CVE-2023-42793 for the first time.

## References

- https://www.jetbrains.com/privacy-security/issues-fixed/
- https://blog.jetbrains.com/teamcity/2023/09/cve-2023-42793-vulnerability-post-mortem/
- https://www.sonarsource.com/blog/teamcity-vulnerability/
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-42793.yaml

## Live exploitation data

The [Live Exploit Tracker page](https://tracker.crowdsec.net/cves/CVE-2023-42793) follows observed exploitation activity for CVE-2023-42793. [Request an API key](https://tracker.crowdsec.net/request-api-key) for full access to its exploitation timeline, attacking IP addresses and blocklists.