CVE-2014-8540 in GitLab
Summary
by MITRE
The groups API in GitLab 6.x and 7.x before 7.4.3 allows remote authenticated guest users to modify ownership of arbitrary groups by leveraging improper permission checks.
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Analysis
by VulDB Data Team • 01/20/2023
The vulnerability identified as CVE-2014-8540 represents a critical authorization flaw within GitLab's group management functionality affecting versions 6.x and 7.x prior to 7.4.3. This security weakness stems from inadequate permission validation mechanisms that permit authenticated guest users to manipulate group ownership attributes. The flaw exists in the groups application programming interface where proper access controls fail to validate whether users possess sufficient privileges to alter group ownership settings, creating a significant vector for privilege escalation attacks.
The technical implementation of this vulnerability exploits the absence of robust authorization checks within GitLab's permission model. Guest users who have authenticated access to the system can leverage the groups API to submit modification requests that alter group ownership assignments without proper verification of their administrative credentials. This improper validation occurs at the application layer where the system fails to cross-reference user roles against the required permissions needed to modify group ownership. The vulnerability specifically affects the API endpoints responsible for group management operations, allowing malicious actors to manipulate group hierarchies and potentially gain elevated privileges within the repository management system.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to gain unauthorized access to sensitive project data and administrative controls. Guest users could potentially reassign group ownership to themselves or other malicious actors, effectively compromising the integrity of the entire GitLab instance. This flaw undermines the fundamental security model of GitLab's access control system and can result in unauthorized data exposure, project manipulation, and potential complete system compromise. The vulnerability is particularly dangerous because it requires minimal privileges to exploit and can be executed remotely, making it an attractive target for attackers seeking to establish persistent access to source code repositories.
From a cybersecurity perspective, this vulnerability aligns with CWE-285, which addresses improper authorization issues in software systems, and maps to several ATT&CK techniques including privilege escalation and persistence mechanisms. Organizations using affected GitLab versions face significant risk of unauthorized access to their source code repositories and development environments. The vulnerability demonstrates a critical flaw in the principle of least privilege implementation where guest users are granted excessive permissions through API endpoints. Mitigation strategies should include immediate upgrade to GitLab 7.4.3 or later versions, implementation of additional access controls, and regular security audits of API endpoints to ensure proper authorization enforcement. Security teams should also consider implementing network-level restrictions and monitoring for unusual group ownership modification activities to detect potential exploitation attempts.