CVE-2023-2022 in Community Edition
Summary
by MITRE • 08/02/2023
An issue has been discovered in GitLab CE/EE affecting all versions starting before 16.0.8, all versions starting from 16.1 before 16.1.3, all versions starting from 16.2 before 16.2.2, which leads to developers being able to create pipeline schedules on protected branches even if they don't have access to merge
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Analysis
by VulDB Data Team • 10/03/2024
This vulnerability in GitLab CE/EE represents a critical access control flaw that undermines the security of protected branches through improper pipeline schedule management. The issue allows developers with insufficient permissions to create automated pipeline schedules on branches that should be restricted to authorized merge contributors only. This misconfiguration creates a pathway for unauthorized automation execution that bypasses the intended security boundaries designed to protect sensitive code repositories. The vulnerability affects multiple version streams including 16.0.x, 16.1.x, and 16.2.x releases, indicating a widespread impact across the GitLab platform's core functionality.
The technical implementation of this flaw stems from inadequate permission validation during pipeline schedule creation processes. When developers attempt to set up automated pipeline schedules on protected branches, the system fails to properly verify whether the requesting user possesses the necessary merge permissions required for such operations. This validation gap occurs at the application level within GitLab's access control mechanisms, where pipeline scheduling functionality does not properly integrate with branch protection rules. The flaw essentially allows users to circumvent the standard merge request approval workflow by creating automated schedules that execute code without proper authorization, creating a persistent security risk.
The operational impact of this vulnerability extends beyond simple permission bypass to potentially enable malicious actors or compromised developers to establish persistent automation on protected code bases. Attackers could exploit this weakness to run automated tests, deployments, or code analysis tools on protected branches without proper authorization, potentially leading to unauthorized code execution or data exposure. This vulnerability directly violates the principle of least privilege and could facilitate privilege escalation attacks where unauthorized users gain access to sensitive production environments through automated pipeline execution. The security implications are particularly severe in enterprise environments where protected branches often contain critical production code or sensitive configuration data.
Organizations should immediately upgrade to GitLab versions 16.0.8, 16.1.3, or 16.2.2 respectively to remediate this vulnerability, as these releases contain the necessary patches to enforce proper access controls for pipeline scheduling operations. Additional mitigations include implementing manual review processes for pipeline schedules on protected branches, monitoring for unauthorized schedule creation activities, and ensuring that branch protection rules are properly configured to prevent automatic pipeline execution without explicit merge permissions. Security teams should also conduct comprehensive audits of existing pipeline schedules to identify any unauthorized configurations that may have been established prior to the patch deployment. This vulnerability aligns with CWE-284 Access Control Issues and maps to ATT&CK technique T1078 Valid Accounts, as it allows unauthorized access through legitimate user accounts with insufficient permissions.
The root cause of this issue demonstrates a fundamental flaw in GitLab's permission model integration, where automated pipeline scheduling does not properly consider branch protection status. This represents a classic case of insufficient input validation and access control enforcement, where the system assumes that users with basic repository access should also have pipeline scheduling privileges without proper authorization checks. The vulnerability's persistence across multiple release branches indicates that the underlying architectural flaw was not properly addressed in the security model implementation, requiring comprehensive code review and security testing of all pipeline-related functionalities to prevent similar issues in the future.