CVE-2020-2118 in Pipeline GitHub Notify Step Plugin
Summary
by MITRE
A missing permission check in Jenkins Pipeline GitHub Notify Step Plugin 1.0.4 and earlier in form-related methods allowed users with Overall/Read access to enumerate credentials ID of credentials stored in Jenkins.
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Analysis
by VulDB Data Team • 02/13/2020
The vulnerability identified as CVE-2020-2118 resides within the Jenkins Pipeline GitHub Notify Step Plugin version 1.0.4 and earlier, representing a critical permission bypass issue that undermines the security posture of Jenkins environments. This flaw specifically affects the form-related methods within the plugin, creating an unauthorized access vector that allows malicious actors with minimal privileges to exploit the system's credential management infrastructure.
The technical flaw manifests through a missing permission check mechanism that should have validated user authorization before exposing sensitive credential information. In normal operations, Jenkins employs a robust permission model where users must possess appropriate access levels to interact with specific system components. However, this vulnerability creates an exception in the form processing functionality of the GitHub Notify Step plugin, where the system fails to verify whether the requesting user has sufficient privileges to access credential identifiers.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers with only Overall/Read access to enumerate credentials stored within Jenkins. This permission level typically grants users the ability to view basic system information and build results but should not provide access to credential management functions. The enumeration capability allows threat actors to discover valid credential IDs that can subsequently be used to craft more sophisticated attacks targeting the Jenkins infrastructure or the systems protected by those credentials.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which describes improper access control mechanisms that allow unauthorized users to access protected resources. The flaw represents a direct violation of the principle of least privilege, where users can access information beyond their designated permissions. Additionally, this vulnerability maps to ATT&CK technique T1552.001, which covers credentials from password stores, as the enumeration of credential IDs essentially provides attackers with a map to locate and potentially exploit stored credentials.
The implications of this vulnerability are particularly severe in enterprise environments where Jenkins serves as a central automation platform managing numerous build processes and integrations with external systems. Attackers who successfully exploit this vulnerability can gain access to credential identifiers that may protect database connections, API keys, container registry access tokens, and other sensitive authentication materials. This information can then be leveraged to escalate privileges or conduct lateral movement within the network infrastructure.
Mitigation strategies for CVE-2020-2118 primarily focus on immediate plugin updates to versions that address the missing permission check. Organizations should prioritize upgrading the Pipeline GitHub Notify Step plugin to versions that implement proper access control validation for form-related methods. Additionally, security administrators should conduct comprehensive audits of all Jenkins plugins to identify similar permission bypass vulnerabilities that may exist in other components. Implementing network segmentation and access controls that limit direct access to Jenkins instances can provide additional defense-in-depth measures. Regular security assessments and penetration testing should be conducted to identify potential privilege escalation vectors that could compromise Jenkins environments and the sensitive information they manage.