CVE-2017-2613 in Jenkins
Summary
by MITRE
jenkins before versions 2.44, 2.32.2 is vulnerable to a user creation CSRF using GET by admins. While this user record was only retained until restart in most cases, administrators' web browsers could be manipulated to create a large number of user records (SECURITY-406).
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Analysis
by VulDB Data Team • 03/13/2023
This vulnerability exists in Jenkins versions prior to 2.44 and 2.32.2, representing a critical cross-site request forgery flaw that allows unauthorized user creation through GET requests. The vulnerability specifically targets administrative functions within the Jenkins web interface, enabling attackers to manipulate administrators' browsers into creating multiple user accounts without their knowledge or consent. The flaw stems from insufficient validation of user requests, particularly when processing user creation operations that should require explicit authentication and authorization. This type of vulnerability falls under CWE-352, which categorizes cross-site request forgery issues as a fundamental web application security weakness. The attack vector exploits the trust relationship between the Jenkins server and administrator browsers, leveraging the fact that administrators often maintain persistent sessions with elevated privileges.
The operational impact of this vulnerability extends beyond simple unauthorized user creation, as it can lead to significant security compromise within Jenkins environments. When administrators' browsers are manipulated to create user accounts, these accounts can persist in memory until the Jenkins service restarts, creating a window of opportunity for attackers to establish persistent access points. The vulnerability particularly affects environments where administrators frequently access Jenkins through web browsers, making it a realistic threat in typical enterprise settings. Attackers can exploit this weakness by crafting malicious links or embedding code that triggers the user creation process when administrators visit compromised web pages or click on malicious links. The security implications are compounded by the fact that these user accounts can potentially be granted varying levels of access depending on how the Jenkins instance is configured, including potential access to build systems, configuration settings, and sensitive project data.
The technical exploitation of this vulnerability demonstrates a failure in implementing proper anti-CSRF measures within the Jenkins user management interface. The system's reliance on GET requests for user creation operations without adequate token validation creates a significant attack surface. According to ATT&CK framework, this represents a technique categorized under T1078 which involves valid accounts usage, potentially enabling attackers to establish footholds within Jenkins environments. The vulnerability also aligns with T1566 which covers spearphishing with a link, as attackers can manipulate administrators into visiting malicious sites that trigger the CSRF attack. Organizations running affected Jenkins versions face a heightened risk of unauthorized access, privilege escalation, and potential data breaches. The persistence of these user accounts until system restart means that attackers can maintain access even if they cannot immediately exploit the created accounts, creating a stealthy attack vector. This vulnerability particularly impacts CI/CD environments where Jenkins serves as a central hub for automated builds and deployments, making it a critical concern for DevOps teams and security administrators.
Mitigation strategies for this vulnerability require immediate implementation of Jenkins updates to versions 2.44 or 2.32.2, which contain the necessary security patches. Organizations should also implement additional defensive measures such as enabling CSRF protection mechanisms within Jenkins, ensuring that all user creation operations require proper authentication tokens, and configuring web application firewalls to monitor for suspicious patterns. Regular security audits of Jenkins configurations should be conducted to verify that anti-CSRF protections are properly implemented and that administrative sessions are adequately secured. Security teams should also consider implementing user behavior analytics to detect unusual patterns in user creation activities that might indicate exploitation attempts. The vulnerability serves as a reminder of the critical importance of maintaining current software versions and implementing defense-in-depth strategies to protect against such attacks. Organizations should also conduct regular security training for administrators to help them recognize potential CSRF attack vectors and maintain awareness of the risks associated with visiting untrusted websites while logged into administrative systems.