CVE-2020-2320 in Plugin Installation Manager Tool
Summary
by MITRE • 12/03/2020
Jenkins Plugin Installation Manager Tool 2.1.3 and earlier does not verify plugin downloads.
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Analysis
by VulDB Data Team • 12/12/2020
The Jenkins Plugin Installation Manager Tool vulnerability represents a critical security flaw in version 2.1.3 and earlier releases where the system fails to validate the integrity and authenticity of plugin downloads. This vulnerability falls under the category of insecure download handling and can be classified as CWE-353, which addresses the failure to verify the integrity of downloaded content. The issue stems from the tool's inability to perform proper cryptographic verification or checksum validation of plugins before installation, creating an exploitable weakness in the Jenkins ecosystem's security posture. Attackers can potentially manipulate plugin downloads to inject malicious code or replace legitimate plugins with compromised versions without detection.
The technical implementation flaw occurs within the plugin installation process where the system accepts and installs plugins based solely on the download URL without performing any verification checks. This design oversight allows for man-in-the-middle attacks where adversaries can intercept plugin downloads and substitute them with malicious variants. The vulnerability is particularly dangerous because it operates at the installation layer, meaning that once a compromised plugin is downloaded and installed, it can execute arbitrary code within the Jenkins environment with the privileges of the Jenkins service account. This creates a persistent backdoor that can be leveraged for further escalation attacks.
The operational impact of this vulnerability extends beyond simple code injection, as it can enable attackers to establish persistent access to Jenkins servers and potentially compromise the entire CI/CD pipeline. The vulnerability affects organizations that rely on automated plugin management, making it particularly concerning for enterprises that depend on Jenkins for their software development workflows. Attackers can exploit this weakness to gain unauthorized access to build servers, steal sensitive code repositories, or manipulate the build process to introduce backdoors into production software. The lack of verification also means that organizations cannot trust the integrity of their plugin installations, potentially leading to supply chain attacks where legitimate plugins are compromised.
Mitigation strategies should focus on immediate remediation through patching to version 2.1.4 or later where the verification mechanism has been implemented. Organizations should also implement network-level protections such as certificate pinning and content filtering to prevent unauthorized modifications to plugin downloads. The implementation of proper checksum validation and digital signatures for all plugins represents a fundamental security improvement that aligns with industry best practices for software supply chain security. Additionally, organizations should consider implementing network segmentation and access controls to limit the impact of potential compromise, as this vulnerability can be exploited through various attack vectors including compromised network infrastructure or DNS hijacking. The vulnerability demonstrates the importance of following secure coding practices and implementing proper input validation and verification mechanisms, which are essential components of the ATT&CK framework's defense-in-depth strategy for preventing supply chain compromises.