CVE-2020-2148 in Mac Plugin
Summary
by MITRE
A missing permission check in Jenkins Mac Plugin 1.1.0 and earlier allows attackers with Overall/Read permission to connect to an attacker-specified SSH server using attacker-specified credentials.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 03/10/2020
The vulnerability described in CVE-2020-2148 represents a critical authorization bypass flaw within the Jenkins Mac Plugin version 1.1.0 and earlier. This issue stems from a fundamental missing permission check that allows unauthorized attackers to exploit the plugin's functionality. The vulnerability specifically affects systems where the Mac Plugin is installed and configured, creating a pathway for attackers to execute malicious actions through SSH connections. The flaw exists in the plugin's implementation of access control mechanisms, where proper authorization validation is absent during critical operations.
The technical implementation of this vulnerability lies in the plugin's failure to properly validate user permissions before executing SSH connection operations. When an attacker with only Overall/Read permission attempts to use the plugin's SSH functionality, the system should reject the request due to insufficient privileges. However, the missing permission check allows the attacker to bypass this restriction and establish connections to arbitrary SSH servers using credentials they control. This behavior violates the principle of least privilege and demonstrates a clear breakdown in Jenkins' access control model.
The operational impact of this vulnerability is significant as it enables attackers to potentially gain unauthorized access to systems that would normally be protected from such connections. An attacker could leverage this vulnerability to establish persistent access points, exfiltrate data, or perform reconnaissance activities against systems within the network. The ability to specify both the target SSH server and the credentials used creates multiple attack vectors and increases the potential damage. This vulnerability essentially allows a low-privilege user to perform high-privilege actions, which is a classic authorization bypass scenario that undermines the entire security architecture of the Jenkins environment.
From a security standards perspective, this vulnerability aligns with CWE-284 which describes improper access control, and it maps to ATT&CK technique T1078 which covers valid accounts for lateral movement. The flaw represents a clear violation of the security principle that users should only be able to perform actions within their authorized permissions. Organizations using Jenkins with the Mac Plugin are particularly vulnerable as this issue affects the core authentication and authorization mechanisms that protect CI/CD pipelines. The vulnerability also highlights the importance of proper input validation and access control implementation in plugin architectures.
Mitigation strategies for CVE-2020-2148 should include immediate patching of the Jenkins Mac Plugin to version 1.1.1 or later where the permission check has been properly implemented. Administrators should also implement network segmentation to limit access to Jenkins servers and restrict SSH connectivity from the Jenkins environment. Additional measures include monitoring for unauthorized SSH connection attempts, implementing strict access controls for Jenkins plugins, and conducting regular security audits of installed plugins. Organizations should also consider implementing principle of least privilege policies and ensuring that only authorized personnel have access to Jenkins configuration and plugin management functions. The vulnerability serves as a reminder of the critical importance of proper access control implementation in security-sensitive applications.