CVE-2012-6072 in Jenkins
Summary
by MITRE
CRLF injection vulnerability in CloudBees Jenkins before 1.491, Jenkins LTS before 1.480.1, and Jenkins Enterprise 1.424.x before 1.424.6.13, 1.447.x before 1.447.4.1, and 1.466.x before 1.466.10.1 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via unspecified vectors.
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Analysis
by VulDB Data Team • 12/29/2021
The CVE-2012-6072 vulnerability represents a critical CRLF injection flaw in CloudBees Jenkins versions prior to specific patch releases, exposing systems to HTTP response splitting attacks that can compromise web application security. This vulnerability affects multiple Jenkins product lines including standard releases, Long Term Support versions, and Enterprise editions across various version ranges, making it a widespread concern for organizations relying on Jenkins for continuous integration and delivery processes. The vulnerability stems from insufficient input validation and sanitization of user-supplied data within Jenkins' HTTP header processing mechanisms, allowing malicious actors to inject carriage return line feed sequences that can manipulate HTTP responses.
The technical exploitation of this vulnerability occurs when Jenkins processes user input that contains CRLF sequences without proper sanitization, enabling attackers to inject arbitrary HTTP headers into responses. This CRLF injection allows for HTTP response splitting attacks where malicious input can cause the web server to send multiple HTTP responses in a single connection, potentially enabling session hijacking, cross-site scripting attacks, and cache poisoning. The vulnerability exists in the core HTTP handling components of Jenkins, particularly in areas where user-provided data is used to construct HTTP headers for responses, making it a fundamental flaw in the application's security architecture. According to CWE standards, this maps to CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('CRLF Injection') which specifically addresses the improper handling of line feed and carriage return characters in HTTP contexts.
The operational impact of this vulnerability is significant for Jenkins installations, as it can lead to complete compromise of web application security and user session data. Attackers can exploit this vulnerability to manipulate HTTP responses, redirect users to malicious sites, inject malicious content into web pages, or perform session fixation attacks. The vulnerability affects both standard and enterprise Jenkins deployments, creating a substantial risk for organizations using these systems for automated build processes, deployment pipelines, and continuous integration workflows. Organizations with Jenkins installations running vulnerable versions face potential exposure to credential theft, data manipulation, and unauthorized access to build artifacts and system configurations.
Mitigation strategies for CVE-2012-6072 require immediate patching of affected Jenkins installations to the recommended secure versions, including Jenkins 1.491, LTS 1.480.1, and specific enterprise patch releases. Organizations should also implement input validation measures at the application level, ensuring that all user-supplied data is properly sanitized before being used in HTTP header construction. Network-level protections such as web application firewalls can provide additional defense in depth, though the most effective solution remains upgrading to patched versions. According to ATT&CK framework, this vulnerability aligns with T1190: Exploit Public-Facing Application, representing a common attack pattern where adversaries target web applications for initial access and privilege escalation. Organizations should conduct comprehensive vulnerability assessments to identify all Jenkins installations and ensure proper patch management procedures are in place to prevent similar issues in the future.