CVE-2020-13263 in Enterprise Edition
Summary
by MITRE
An authorization issue relating to project maintainer impersonation was identified in GitLab EE 9.5 and later through 13.0.1 that could allow unauthorized users to impersonate as a maintainer to perform limited actions.
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Analysis
by VulDB Data Team • 10/26/2020
This authorization flaw in GitLab Enterprise Edition represents a critical privilege escalation vulnerability that undermines the platform's access control mechanisms. The vulnerability exists in versions 9.5 through 13.0.1, indicating a prolonged window of exposure where organizations could have been compromised. The issue specifically allows unauthorized users to impersonate project maintainers, which creates a significant security risk in collaborative development environments where maintainers typically possess elevated permissions and responsibilities.
The technical nature of this vulnerability stems from improper authorization checks within the GitLab application's permission system. When users attempt to perform actions within project contexts, the system should verify that the requesting user has appropriate maintainer-level privileges before granting access. However, the flaw enables attackers to bypass these checks through manipulation of request parameters or session handling mechanisms. This type of authorization bypass aligns with CWE-285, which addresses improper authorization issues in software systems. The vulnerability specifically affects the project maintainer role, which typically includes permissions to manage project settings, approve merge requests, and control access to repository resources.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it allows attackers to perform limited actions with maintainer privileges. While the scope is described as "limited," the implications are significant for development workflows where maintainers have substantial control over project integrity. Attackers could potentially manipulate project configurations, approve malicious code changes, or interfere with development processes. This vulnerability directly impacts the principle of least privilege and could facilitate further attacks within the development environment. The attack pattern aligns with ATT&CK technique T1078.004, which covers valid accounts used for unauthorized access, as the impersonation occurs through legitimate user accounts that are elevated to maintainer status through the vulnerability.
Organizations using affected GitLab versions should immediately implement mitigations including upgrading to patched versions where available. The vulnerability demonstrates the importance of regular security updates and proper access control validation. Administrators should also conduct thorough audits of project permissions and monitor for unusual activity patterns that might indicate exploitation attempts. Additional protective measures include implementing multi-factor authentication for privileged accounts and establishing more granular access controls. The incident underscores the critical need for continuous security testing and validation of authorization mechanisms within collaborative platforms. Organizations should also consider implementing network-level monitoring to detect anomalous behavior patterns that could indicate unauthorized maintainer impersonation attempts.