CVE-2022-36909 in OpenShift Deployer Plugin
Summary
by MITRE • 07/27/2022
A missing permission check in Jenkins OpenShift Deployer Plugin 1.2.0 and earlier allows attackers with Overall/Read permission to check for the existence of an attacker-specified file path on the Jenkins controller file system and to upload a SSH key file from the Jenkins controller file system to an attacker-specified URL.
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Analysis
by VulDB Data Team • 08/28/2022
The vulnerability identified as CVE-2022-36909 represents a critical authorization bypass in the Jenkins OpenShift Deployer Plugin, affecting versions 1.2.0 and earlier. This flaw stems from a missing permission check that allows unauthorized users with only Overall/Read permission to perform actions that should require elevated privileges. The vulnerability operates at the intersection of inadequate access control mechanisms and improper privilege enforcement, creating a pathway for attackers to escalate their privileges within the Jenkins environment. The issue manifests through two distinct but related attack vectors that together enable reconnaissance and data exfiltration capabilities.
The technical implementation of this vulnerability exploits the absence of proper validation within the plugin's file handling functions. When an attacker with Overall/Read permission makes specific API calls to the plugin's endpoints, the system fails to verify whether the user possesses the necessary permissions to perform file system operations. This missing validation allows the attacker to enumerate file paths on the Jenkins controller's file system, effectively enabling directory traversal and file discovery attacks. The vulnerability specifically targets the plugin's ability to check file existence and upload SSH key files, creating a potential attack chain that could lead to further compromise of the Jenkins infrastructure.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to exfiltrate sensitive SSH key material from the Jenkins controller. This represents a significant risk to organizations that rely on Jenkins for continuous integration and deployment processes, as SSH keys are fundamental to authentication and access control within automated systems. The ability to upload SSH key files to external attacker-controlled URLs creates a persistent threat vector that could enable long-term access to target systems. This vulnerability aligns with CWE-284, which addresses improper access control, and specifically relates to the broader category of privilege escalation through insufficient authorization checks.
The attack scenario begins with an attacker gaining access to a Jenkins instance with minimal privileges, typically through legitimate user accounts or compromised credentials. Once authenticated, the attacker can leverage the missing permission check to probe the file system structure and identify sensitive files, particularly those containing SSH keys or other authentication material. The subsequent ability to upload these files to external URLs creates a direct data exfiltration pathway that could compromise the entire Jenkins infrastructure and potentially extend to connected systems. This vulnerability demonstrates the critical importance of principle of least privilege implementation and proper input validation in security-critical applications.
Organizations should immediately upgrade to Jenkins OpenShift Deployer Plugin version 1.2.1 or later, which includes the necessary permission checks to prevent unauthorized file system operations. System administrators should also implement network segmentation and monitoring to detect unusual file system access patterns and data exfiltration attempts. The vulnerability's classification under ATT&CK technique T1566.001, which covers credential harvesting through file system access, highlights the need for comprehensive monitoring of file system operations. Additionally, organizations should review their Jenkins permission configurations to ensure that users have only the minimum required privileges and that all plugin installations undergo thorough security assessments before deployment. Regular security audits of Jenkins plugins and configurations should be conducted to identify and remediate similar authorization bypass vulnerabilities.