What is CVE-2024-27198?

An authentication bypass vulnerability in JetBrains TeamCity allows unauthenticated attackers to gain admin access and execute arbitrary code on the server via the web UI.

How do I fix CVE-2024-27198?

Update TeamCity to 2023.11.4 or later immediately. Restrict TeamCity web UI access to trusted IP ranges only. Audit TeamCity user accounts and remove any unauthorized admin accounts. Rotate all credentials, tokens, and VCS passwords stored in TeamCity. Review build logs for signs of exploitation (unauthorized builds, new admin accounts). Enable TeamCity audit logs and set up alerts for admin account creation.

Which versions are affected by CVE-2024-27198?

Affected: TeamCity < 2023.11.4. Fixed in: TeamCity 2023.11.4+.

criticalCVSS 10/10·Published: 2024-03-04·JetBrains TeamCity

How to fix CVE-2024-27198 – Step-by-Step Guide

CVE-2024-27198 is a critical authentication bypass vulnerability in JetBrains TeamCity. This flaw allows unauthenticated attackers to gain administrative access and execute arbitrary code on affected servers.

CVE ID

CVE-2024-27198

Severity

CRITICAL

CVSS Score

10/10

Affected

JetBrains TeamCity

What is JetBrains TeamCity Authentication Bypass?

This vulnerability, named JetBrains TeamCity Authentication Bypass, stems from a flaw in the web UI of JetBrains TeamCity. It permits unauthenticated users to bypass authentication mechanisms, escalating privileges to full administrator access. Attackers can then leverage this access to execute arbitrary code on the underlying server.

Affected Versions

TeamCity < 2023.11.4

Fixed In

TeamCity 2023.11.4+

Official References

Impact and Risks for your Infrastructure

The impact is a complete server takeover, leading to severe business and infrastructure risks. Attackers can create admin accounts, access sensitive source code, exfiltrate secrets, and disrupt CI/CD pipelines, compromising data integrity and confidentiality.

teamcityauth-bypasscriticalci-cd2024

Step-by-Step Mitigation Guide

To fix CVE-2024-27198, immediately upgrade your JetBrains TeamCity instance to version 2023.11.4 or newer. Verify the update by checking the installed version in the TeamCity UI and confirming the patch notes address this CVE.

1Update TeamCity to 2023.11.4 or later immediately.
2Restrict TeamCity web UI access to trusted IP ranges only.
3Audit TeamCity user accounts and remove any unauthorized admin accounts.
4Rotate all credentials, tokens, and VCS passwords stored in TeamCity.
5Review build logs for signs of exploitation (unauthorized builds, new admin accounts).
6Enable TeamCity audit logs and set up alerts for admin account creation.

Frequently Asked Questions

What is the CVSS score for CVE-2024-27198?▼

CVE-2024-27198 has a CVSS score of 10/10 (critical severity). This reflects the most severe potential impact, requiring immediate remediation.

Which versions of JetBrains TeamCity are affected?▼

Affected: TeamCity < 2023.11.4. The vulnerability was fixed in: TeamCity 2023.11.4+.

How long does it take to fix CVE-2024-27198?▼

For most teams: 15–60 minutes to apply the patch, plus 15 minutes of post-patch verification. Complex multi-service environments may require 2–4 hours including staging validation.

Is CVE-2024-27198 being actively exploited?▼

Check the NVD entry and CISA KEV catalog for exploitation status. As a critical-severity vulnerability, treat it as a priority remediation regardless of known exploitation status.

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This CVE fix guide is based on publicly available security advisories (NVD, vendor bulletins). Always test changes in a staging environment before applying to production. Verify against the official vendor advisory for the most up-to-date guidance.