CVE-2016-3725 in Jenkins
Summary
by MITRE
CloudBees Jenkins before 2.3 and LTS before 1.651.2 allows remote authenticated users to trigger updating of update site metadata by leveraging a missing permissions check. NOTE: this issue can be combined with DNS cache poisoning to cause a denial of service (service disruption).
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Analysis
by VulDB Data Team • 08/19/2022
The vulnerability identified as CVE-2016-3725 affects CloudBees Jenkins versions prior to 2.3 and LTS versions prior to 1.651.2, representing a significant security flaw in the Jenkins continuous integration and delivery platform. This issue stems from a missing permissions check that allows authenticated users to manipulate update site metadata, creating a potential vector for service disruption and denial of service attacks. The vulnerability specifically targets the update center functionality within Jenkins, which is responsible for managing plugin updates and system metadata from remote repositories.
The technical flaw manifests through an insufficient access control mechanism that fails to properly validate user permissions before allowing update site metadata operations. When authenticated users leverage this weakness, they can trigger unauthorized updates to the Jenkins update site metadata, potentially corrupting the update process or redirecting users to malicious repositories. This missing permissions check represents a clear violation of the principle of least privilege and demonstrates inadequate input validation within the update center component. The vulnerability is categorized under CWE-284, which addresses improper access control, and aligns with ATT&CK technique T1070.004 for Indicator Removal on Host and T1499.004 for Endpoint Denial of Service.
The operational impact of this vulnerability extends beyond simple metadata manipulation, as it can be exploited in combination with DNS cache poisoning techniques to create a comprehensive denial of service scenario. When combined with DNS cache poisoning, an attacker can not only trigger unauthorized metadata updates but also redirect Jenkins to malicious update sites, potentially leading to the installation of compromised plugins or complete system compromise. This combination of vulnerabilities creates a particularly dangerous attack vector that can disrupt critical development workflows and CI/CD processes. Organizations relying on Jenkins for automated build and deployment operations face significant risk of service disruption, as the update center functionality is frequently accessed during routine operations.
Mitigation strategies for CVE-2016-3725 require immediate patching of affected Jenkins installations to versions 2.3 and LTS 1.651.2 or later, which contain the necessary permissions checks to prevent unauthorized metadata updates. Administrators should also implement network-level protections such as DNS filtering and network segmentation to reduce the impact of potential DNS cache poisoning attacks. Additional defensive measures include monitoring update center activities for unusual patterns, implementing proper access controls for Jenkins administrators, and regularly auditing Jenkins configurations to ensure proper privilege management. The vulnerability highlights the importance of maintaining up-to-date software components and demonstrates how seemingly minor access control oversights can create significant security risks in enterprise environments. Organizations should also consider implementing automated patch management systems to ensure timely remediation of similar vulnerabilities in the future.