CVE-2020-2309 in Kubernetes Plugin
Summary
by MITRE • 11/04/2020
A missing/An incorrect permission check in Jenkins Kubernetes Plugin 1.27.3 and earlier allows attackers with Overall/Read permission to enumerate credentials IDs of credentials stored in Jenkins.
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Analysis
by VulDB Data Team • 12/02/2020
The vulnerability described in CVE-2020-2309 represents a critical permission bypass issue within the Jenkins Kubernetes Plugin ecosystem. This flaw affects versions 1.27.3 and earlier, where the plugin fails to properly validate user permissions when processing credential enumeration requests. The vulnerability stems from inadequate access control mechanisms that allow unprivileged users to discover credential identifiers within the Jenkins environment, potentially exposing sensitive authentication information.
This security weakness manifests as a missing permission check that should normally restrict credential enumeration to users with appropriate administrative privileges. The vulnerability specifically impacts users who possess only Overall/Read permission, which typically grants read access to basic Jenkins functionality but should not permit credential discovery operations. The flaw enables attackers to systematically identify credential IDs stored within Jenkins, creating a pathway for further exploitation attempts. The technical implementation appears to lack proper authorization validation before exposing credential metadata, which violates fundamental security principles of least privilege and access control enforcement.
The operational impact of this vulnerability extends beyond simple information disclosure, as credential enumeration provides attackers with critical intelligence for subsequent attack phases. Once credential IDs are discovered, attackers can potentially attempt credential reuse attacks or focus their efforts on specific credential targets. This vulnerability aligns with CWE-284, which addresses improper access control, and demonstrates how insufficient permission validation can create security boundaries that allow unauthorized access to sensitive information. The attack surface is particularly concerning in environments where Jenkins serves as a central automation hub, as credential exposure can lead to broader compromise of CI/CD pipelines and underlying infrastructure.
Organizations should immediately upgrade to Jenkins Kubernetes Plugin version 1.27.4 or later, which contains the necessary permission check fixes. Additionally, administrators should implement comprehensive monitoring for credential enumeration attempts and review existing user permissions to ensure proper access control enforcement. The vulnerability highlights the importance of validating all access control decisions at multiple layers of the application architecture. Security teams should also consider implementing network-level controls to limit access to Jenkins endpoints and establish automated scanning procedures to detect similar permission bypass issues in other plugins and components. This incident underscores the necessity of following ATT&CK framework principles for credential access and emphasizes the critical need for proper permission validation in enterprise automation platforms.