CVE-2024-27199 - Critical Path Traversal Vulnerability in JetBrains TeamCity Before 2023.11.4 Allows Limited Administrative Actions

The cybersecurity community recently discovered a critical vulnerability in JetBrains TeamCity, a widely-used continuous integration and deployment server, which has been assigned the identifier CVE-2024-27199. This security issue could allow attackers to perform limited administrative actions by exploiting a path traversal vulnerability. This post will outline the details of this vulnerability, demonstrate how it can be exploited, and provide guidance on how to protect your systems from potential attacks. Links to original references and code snippets are also included.

Overview

According to the CVE database, the vulnerability is classified as a path traversal flaw, which means that a malicious user could potentially exploit this flaw to access unauthorized system files and perform unintended actions. Specifically, the flaw affects JetBrains TeamCity versions before 2023.11.4.

JetBrains has acknowledged the vulnerability and provided a patch to resolve the issue in their latest update. You can find the official security advisory from JetBrains here.

How It Works: Exploiting CVE-2024-27199

A path traversal vulnerability allows an attacker to navigate the directory structure of a target system by manipulating input values that are used to construct file and directory paths. In the case of CVE-2024-27199, the vulnerability exists due to improper handling of user-supplied input by the affected TeamCity server.

An attacker could take advantage of this flaw by submitting malicious input designed to force the server to access specific files and directories. This, in turn, would let the attacker perform limited administrative actions, possibly compromising the integrity and security of the TeamCity instance. Here's an example of a potential exploit using a crafted input string:

http://vulnerable_teamcity_server.example.com/controller?action=traverse&path=../../../../unauthorized/directory

In this example, the "path" parameter in the URL contains traversal characters (i.e., "../../../") that force the server to access files and directories outside of the intended scope. Combining this with other techniques could potentially lead to a significant compromise of the vulnerable server.

Mitigations and Best Practices

To protect your JetBrains TeamCity server from the CVE-2024-27199 vulnerability and similar exploitation attempts, we recommend taking the following steps:

1. Update your JetBrains TeamCity server to the latest version (v2023.11.4), which includes the security patch for CVE-2024-27199. You can find the update files and instructions on JetBrains' website: TeamCity Downloads.

2. Verify that your server is running the latest security updates for all its components, including the operating system and any third-party tools or libraries.

3. Configure your security settings to restrict access to sensitive files and directories within your TeamCity installation. Ensure that access is only granted to authorized users and limit their permissions according to the principle of least privilege.

4. Regularly review your server logs and monitor for suspicious activity, including signs of unauthorized access or data manipulation.

5. Maintain a robust backup plan to ensure quick recovery in the event of a security breach or data loss.

By following these best practices, you can help ensure the security and integrity of your TeamCity instance and maintain a robust defense against potential attacks.

Wrapping Up

CVE-2024-27199 is a critical vulnerability that could allow attackers to perform unauthorized actions on JetBrains TeamCity servers running versions before 2023.11.4. By understanding the nature of this flaw and implementing the recommended security measures, you can protect your servers and maintain a strong security posture against potential attacks.

In this post, we have provided insight into the vulnerability, demonstrated its potential exploitation, and shared best practices for mitigating the risks associated with CVE-2024-27199. Stay vigilant and be proactive in protecting your critical infrastructure from emerging threats.

Timeline

Published on: 03/04/2024 18:15:09 UTC
Last modified on: 03/11/2024 15:15:47 UTC