CVE-2020-2131 in Harvest SCM Plugin
Summary
by MITRE
Jenkins Harvest SCM Plugin 0.5.1 and earlier stores passwords unencrypted in job config.xml files on the Jenkins master where they can be viewed by users with Extended Read permission, or access to the master file system.
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Analysis
by VulDB Data Team • 02/13/2020
The vulnerability identified as CVE-2020-2131 affects the Jenkins Harvest SCM Plugin version 0.5.1 and earlier, presenting a critical security flaw in how authentication credentials are handled within the Jenkins continuous integration environment. This issue stems from the plugin's improper storage mechanism for passwords, which are persisted in plain text format within the job configuration files on the Jenkins master server. The vulnerability specifically impacts organizations that utilize Harvest SCM plugin for source code management integration within their Jenkins pipelines, creating a significant risk exposure for any system where job configurations contain sensitive authentication information.
The technical implementation flaw resides in the plugin's configuration handling process where user credentials including passwords are stored without any form of encryption or obfuscation within the job config.xml files. When Jenkins processes job configurations that include Harvest SCM plugin settings, the authentication details are written directly to the filesystem in clear text format, making them immediately accessible to any user or process that can read the configuration files. This design decision violates fundamental security principles for credential management and represents a clear violation of the principle of least privilege, as users with merely Extended Read permission can access these sensitive credentials through normal job configuration viewing operations.
The operational impact of this vulnerability extends beyond simple credential exposure, creating multiple attack vectors for malicious actors within the Jenkins environment. Users with Extended Read permission can directly access job configuration files through the Jenkins web interface or by accessing the master file system directly, potentially gaining access to multiple sets of credentials across different jobs and projects. This exposure allows for privilege escalation attacks where attackers can leverage these credentials to access external systems, repositories, or services that the Jenkins jobs interact with, potentially leading to complete compromise of the source code management infrastructure. The vulnerability also affects the principle of defense in depth, as it creates a single point of failure where credential exposure can lead to broader system compromise, making it particularly dangerous in enterprise environments where Jenkins masters may be shared across multiple teams and projects.
Organizations should immediately implement multiple mitigation strategies to address this vulnerability, beginning with immediate patching of the Harvest SCM plugin to version 0.5.2 or later where the encryption issue has been resolved. The recommended approach involves disabling the affected plugin entirely if immediate patching is not feasible, while also implementing strict access controls to limit who can view job configurations through Extended Read permissions. System administrators should conduct comprehensive audits of existing job configurations to identify and remediate any instances where passwords may have been stored in clear text, potentially requiring manual credential rotation for affected systems. Additionally, organizations should implement monitoring solutions to detect unauthorized access attempts to job configuration files and establish regular security reviews of Jenkins plugin configurations to prevent similar issues from occurring in other third-party integrations. This vulnerability aligns with CWE-312 (Cleartext Storage of Sensitive Information) and represents a significant risk under ATT&CK framework category TA0006 (Credential Access) where adversaries can exploit weak credential storage mechanisms to gain unauthorized access to sensitive systems and data.