CVE-2014-3662 in Jenkins
Summary
by MITRE
CloudBees Jenkins before 1.583 and LTS before 1.565.3 allows remote attackers to enumerate user names via vectors related to login attempts.
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Analysis
by VulDB Data Team • 03/30/2022
The vulnerability described in CVE-2014-3662 represents a significant information disclosure issue within CloudBees Jenkins continuous integration platform versions prior to 1.583 and LTS versions before 1.565.3. This flaw enables remote attackers to perform user enumeration through login attempt mechanisms, effectively allowing unauthorized parties to discover valid user accounts within the system. The vulnerability stems from the application's insufficient handling of authentication attempts and response variations that reveal whether a username exists in the system.
The technical implementation of this vulnerability lies in how Jenkins processes authentication requests and generates responses for login attempts. When a user attempts to log in with a valid username but incorrect password, the system provides a different response compared to when an invalid username is submitted. This differential response behavior creates a timing or content-based side channel that attackers can exploit to systematically test usernames and identify which ones are valid within the Jenkins instance. The flaw directly maps to CWE-200, which addresses information exposure through improper error handling, and represents a classic example of how authentication mechanisms can inadvertently leak sensitive information about system users.
From an operational impact perspective, this vulnerability significantly weakens the security posture of Jenkins installations by providing attackers with a straightforward method to enumerate valid user accounts. Once attackers have identified legitimate usernames, they can proceed with targeted attacks such as password spraying, credential stuffing, or more sophisticated brute force attempts against the discovered accounts. The vulnerability affects both standard and long-term support releases, indicating it was a persistent issue that required multiple version updates to address properly. This enumeration capability directly supports the attacker's initial reconnaissance phase and can facilitate subsequent compromise of the Jenkins instance or related systems where these credentials might be reused.
The mitigation strategy for this vulnerability involves upgrading to the patched versions of Jenkins as specified in the CVE description, with version 1.583 and LTS 1.565.3 representing the minimum required releases to address the issue. Organizations should also implement additional security controls such as rate limiting for authentication attempts, account lockout mechanisms, and monitoring for unusual login patterns. The vulnerability demonstrates the importance of proper error handling in authentication systems and aligns with ATT&CK technique T1078 which covers valid accounts as a means of gaining access to systems. Security teams should also consider implementing network-level controls to limit access to Jenkins instances and ensure that authentication mechanisms do not provide information that could aid in account enumeration attacks.
The broader implications of this vulnerability extend beyond the immediate Jenkins installation, as it highlights how seemingly minor implementation flaws in authentication systems can create significant security risks. The vulnerability serves as a reminder of the importance of thorough security testing of authentication flows and the need for consistent error handling that does not reveal system internals. Organizations running Jenkins or similar continuous integration platforms should conduct comprehensive security assessments to identify similar vulnerabilities in their authentication mechanisms and ensure proper patch management processes are in place to address such issues promptly.