CVE-2016-0792 in Jenkins
Summary
by MITRE
Multiple unspecified API endpoints in CloudBees Jenkins before 1.650 and LTS before 1.642.2 allow remote authenticated users to execute arbitrary code via serialized data in an XML file, related to XStream and groovy.util.Expando.
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Analysis
by VulDB Data Team • 08/15/2024
The vulnerability identified as CVE-2016-0792 represents a critical remote code execution flaw affecting CloudBees Jenkins versions prior to 1.650 and LTS versions before 1.642.2. This vulnerability stems from insecure deserialization practices within Jenkins' API endpoints, specifically involving the XStream library and groovy.util.Expando objects. The flaw allows authenticated attackers to craft malicious XML payloads that, when processed by the vulnerable Jenkins instances, execute arbitrary code on the server. This type of vulnerability falls under the CWE-502 category for deserialization of untrusted data, which is a well-documented and dangerous class of security issues that has been extensively covered in security literature and frameworks.
The technical exploitation of this vulnerability leverages the XStream library's ability to deserialize Java objects from XML representations without proper validation. When Jenkins processes API requests containing serialized data, particularly those involving groovy.util.Expando objects, the system fails to adequately sanitize or validate the incoming serialized content. Attackers can craft malicious XML files that, when submitted through various API endpoints, trigger the deserialization process and execute arbitrary code with the privileges of the Jenkins service account. This attack vector is particularly dangerous because it requires only authenticated access, meaning that any user with valid credentials to the Jenkins instance can potentially exploit this vulnerability, making it a significant risk for organizations where Jenkins is used for continuous integration and deployment processes.
The operational impact of CVE-2016-0792 extends far beyond simple code execution, as it provides attackers with complete control over the affected Jenkins servers. This compromise can lead to unauthorized access to source code repositories, theft of build artifacts, manipulation of continuous integration pipelines, and potential lateral movement within the network. The vulnerability is particularly concerning in enterprise environments where Jenkins serves as a central component of DevOps workflows, as it can enable attackers to disrupt development processes, compromise build integrity, and potentially access sensitive production systems. Organizations using Jenkins for automated deployment processes face the additional risk of supply chain attacks where malicious code can be injected into the build pipeline and distributed to production environments.
Mitigation strategies for CVE-2016-0792 primarily focus on immediate version upgrades to Jenkins 1.650 or LTS 1.642.2 and later releases where the vulnerability has been patched. Organizations should also implement network segmentation to limit access to Jenkins instances, enforce strict authentication controls, and regularly audit API endpoint access. The remediation process should include disabling unnecessary API endpoints and implementing proper input validation for all serialized data processing. Security teams should also consider implementing web application firewalls and monitoring for suspicious API activity patterns that might indicate exploitation attempts. This vulnerability aligns with ATT&CK technique T1059.007 for command and script interpreter, as the exploitation results in arbitrary command execution on the target system, and represents a classic example of how insecure deserialization can lead to complete system compromise in CI/CD environments.