CVE-2019-6787 in Community Edition
Summary
by MITRE
An Incorrect Access Control issue was discovered in GitLab Community and Enterprise Edition before 11.5.8, 11.6.x before 11.6.6, and 11.7.x before 11.7.1. The GitLab API allowed project Maintainers and Owners to view the trigger tokens of other project users.
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Analysis
by VulDB Data Team • 09/23/2023
The vulnerability identified as CVE-2019-6787 represents a critical access control flaw within GitLab's API implementation that affected multiple versions of both Community and Enterprise editions. This issue stems from improper authorization checks within the GitLab platform's trigger token management system, creating a scenario where users with elevated privileges could access sensitive information belonging to other users within the same project. The flaw specifically impacted versions prior to 11.5.8, 11.6.6, and 11.7.1 respectively, indicating a widespread vulnerability that affected a significant portion of GitLab's user base during that period. The access control mechanism failed to properly validate user permissions when requesting trigger token information, allowing unauthorized access to credentials that should have remained restricted to specific authorized personnel.
The technical nature of this vulnerability aligns with CWE-284, which categorizes improper access control issues in software systems. This particular flaw falls under the broader category of privilege escalation through insufficient authorization checks, where maintainers and owners could exploit a gap in the API's permission model to retrieve trigger tokens belonging to other users. Trigger tokens in GitLab serve as authentication mechanisms for CI/CD pipeline triggers, making them highly sensitive credentials that could potentially be leveraged for unauthorized system access. The vulnerability exploited a lack of proper user context validation within the API endpoints responsible for trigger token retrieval, allowing authenticated users with maintainer or owner roles to bypass normal access restrictions and query token information for unrelated project members.
The operational impact of this vulnerability extends beyond simple information disclosure, as trigger tokens represent critical authentication mechanisms within GitLab's continuous integration and deployment pipelines. Attackers who could access these tokens could potentially manipulate CI/CD processes, trigger unauthorized builds, or gain deeper access to project resources that were protected by the token-based authentication system. This vulnerability particularly affects organizations that rely heavily on GitLab's pipeline automation features, as compromised trigger tokens could enable attackers to execute malicious code within the CI/CD environment or manipulate build processes. The issue also presents a significant risk to organizations that use GitLab for managing sensitive projects, as the exposure of trigger tokens could lead to unauthorized access to production environments or data breaches through compromised pipeline configurations.
Organizations affected by CVE-2019-6787 should implement immediate mitigations including upgrading to patched versions of GitLab where the access control has been properly enforced. The vulnerability demonstrates the importance of proper input validation and authorization checks within API endpoints, particularly those handling sensitive authentication credentials. Security teams should conduct thorough audits of their GitLab installations to identify and revoke any compromised trigger tokens, while also implementing monitoring for unauthorized API access patterns. The issue also highlights the necessity of following principle of least privilege concepts in software design, ensuring that users only have access to resources necessary for their specific role within the system. Additionally, organizations should consider implementing additional security controls such as API rate limiting and enhanced logging to detect and prevent similar unauthorized access attempts in the future, as this vulnerability could potentially be exploited as part of broader attack campaigns targeting DevOps environments and CI/CD systems.