CVE-2024-43044 in Jenkins
Summary
by MITRE • 08/07/2024
Jenkins 2.470 and earlier, LTS 2.452.3 and earlier allows agent processes to read arbitrary files from the Jenkins controller file system by using the `ClassLoaderProxy#fetchJar` method in the Remoting library.
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Analysis
by VulDB Data Team • 08/17/2024
This vulnerability exists within Jenkins continuous integration and delivery platform where version 2.470 and earlier, as well as LTS version 2.452.3 and earlier, are affected by a critical security flaw. The issue stems from the Remoting library's ClassLoaderProxy#fetchJar method which permits unauthorized file access from the Jenkins controller's file system. This represents a significant privilege escalation vulnerability that allows remote attackers to potentially access sensitive data, configuration files, and other system resources that should normally be restricted to authorized users only. The flaw essentially enables an attacker to bypass normal access controls and retrieve arbitrary files from the controller's file system through the agent processes.
The technical implementation of this vulnerability involves the ClassLoaderProxy#fetchJar method which is designed to handle jar file retrieval operations within the distributed Jenkins architecture. However, the method fails to properly validate file paths or implement adequate access controls when processing requests from agent processes. This allows malicious agents or compromised agents to submit crafted requests that can traverse the file system and access files that should be restricted. The vulnerability is particularly dangerous because it operates at the core of Jenkins' distributed architecture where agents communicate with the controller and the trust relationship between them is exploited to gain unauthorized access. This flaw aligns with CWE-22 weakness category which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal attacks. The vulnerability demonstrates how insecure deserialization and improper input validation can lead to privilege escalation in distributed systems.
The operational impact of CVE-2024-43044 is severe and far-reaching for organizations utilizing affected Jenkins versions. Attackers can potentially access sensitive information including build scripts, source code repositories, configuration files, credential stores, and other critical system data that may contain authentication tokens, API keys, or other confidential information. The vulnerability can be exploited remotely without requiring authentication, making it particularly dangerous in environments where Jenkins is exposed to untrusted networks. Organizations may experience data breaches, intellectual property theft, and potential compromise of their entire CI/CD pipeline infrastructure. The attack vector is particularly concerning because it leverages the legitimate agent-controller communication mechanism to perform unauthorized operations, making detection more difficult and potentially allowing attackers to maintain persistent access. This vulnerability directly maps to several ATT&CK techniques including T1059.001 Command and Scripting Interpreter and T1566.001 Phishing, as attackers can use the compromised system to exfiltrate data or establish further footholds within the network infrastructure.
Organizations should immediately upgrade to Jenkins versions 2.471 or later for the standard release and 2.452.4 or later for the LTS release to remediate this vulnerability. System administrators should also implement network segmentation to limit access to Jenkins controllers and ensure that only trusted agents can communicate with the controller. Additional mitigations include implementing proper access controls, monitoring for unusual file access patterns, and conducting regular security audits of Jenkins configurations. Organizations should also consider implementing network-level firewalls and intrusion detection systems to monitor for exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date software and following secure coding practices in distributed systems where trust relationships between components can be exploited. Regular security assessments and penetration testing should be conducted to identify and remediate similar vulnerabilities in the broader infrastructure ecosystem.