CVE-2023-49652 in Google Compute Engine Plugin
Summary
by MITRE • 11/29/2023
Incorrect permission checks in Jenkins Google Compute Engine Plugin 4.550.vb_327fca_3db_11 and earlier allow attackers with global Item/Configure permission (while lacking Item/Configure permission on any particular job) to enumerate system-scoped credentials IDs of credentials stored in Jenkins and to connect to Google Cloud Platform using attacker-specified credentials IDs obtained through another method, to obtain information about existing projects. This fix has been backported to 4.3.17.1.
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Analysis
by VulDB Data Team • 12/20/2023
The vulnerability described in CVE-2023-49652 represents a critical authorization bypass flaw within the Jenkins Google Compute Engine Plugin, specifically affecting versions up to 4.550.vb_327fca_3db_11. This issue stems from inadequate permission validation mechanisms that allow malicious actors to circumvent expected security controls. The flaw particularly impacts environments where Jenkins administrators have implemented role-based access controls with granular permissions, creating a scenario where users with limited privileges can still access sensitive system information.
The technical implementation of this vulnerability resides in the plugin's handling of credential enumeration and access control checks. Attackers with global Item/Configure permission but without specific job-level Item/Configure privileges can exploit a logic flaw in the credential validation process. This misconfiguration allows the system to reveal credential IDs from the Jenkins credential store that would normally be restricted to authorized users. The vulnerability operates at the intersection of insufficient input validation and improper access control enforcement, creating an information disclosure channel that can be leveraged for further attacks.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables attackers to gain insights into the Google Cloud Platform environment through credential enumeration. When combined with other reconnaissance techniques, an attacker can use the exposed credential IDs to attempt connections to Google Cloud resources, potentially revealing project structures, resource configurations, and other sensitive information. This capability significantly increases the attack surface for cloud-based Jenkins deployments and can lead to unauthorized access to cloud resources, data exfiltration, or further compromise of the cloud infrastructure.
The security implications of this vulnerability align with CWE-284, which addresses improper access control, and can be mapped to ATT&CK techniques including T1528 (Steal Application Access Token) and T1083 (File and Directory Discovery) through the credential enumeration and system information gathering aspects. Organizations utilizing Jenkins with Google Compute Engine plugin are particularly at risk, as this flaw can be exploited by users who have limited but sufficient permissions to cause significant damage to cloud security posture and potentially lead to broader system compromise.
Mitigation strategies should prioritize immediate plugin updates to version 4.3.17.1 or later, where the fix has been implemented to properly enforce credential access controls. System administrators should also review and tighten global permission assignments, ensuring that users with Item/Configure permissions are carefully evaluated and restricted to prevent unauthorized access to system-level resources. Additional monitoring should be implemented to detect unusual credential enumeration patterns or unauthorized access attempts to Google Cloud resources through Jenkins, providing early detection of potential exploitation attempts.