CVE-2019-15591 in Community Edition
Summary
by MITRE
An improper access control vulnerability exists in GitLab <12.3.3 that allows an attacker to obtain container and dependency scanning reports through the merge request widget even though public pipelines were disabled.
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Analysis
by VulDB Data Team • 03/15/2024
This vulnerability resides in GitLab versions prior to 12.3.3 and represents a critical access control flaw that undermines the platform's security model for container and dependency scanning reports. The issue manifests when public pipelines are disabled within a project configuration, yet attackers can still retrieve sensitive scanning information through the merge request widget interface. This misconfiguration creates an unauthorized data exposure channel that bypasses intended security boundaries and demonstrates a fundamental flaw in the access control implementation.
The technical root cause stems from insufficient validation of user permissions within the merge request widget component. When public pipelines are disabled, the system should prevent unauthorized access to associated scanning reports regardless of the interface through which requests are made. However, the vulnerability allows attackers to exploit the widget's functionality to access container and dependency scanning data that should only be available to authorized project members or administrators. This flaw operates at the application layer and directly violates the principle of least privilege, where users should only access resources necessary for their role.
The operational impact of this vulnerability extends beyond simple information disclosure, as container and dependency scanning reports often contain sensitive data about software dependencies, security vulnerabilities, and potentially exploitable weaknesses in the codebase. Attackers can leverage this access to gain intelligence about target applications, identify potential attack vectors, and understand the security posture of projects they are not authorized to access. The vulnerability particularly affects organizations that rely on GitLab's security scanning features while maintaining strict access controls, as it creates an unexpected backdoor for unauthorized information retrieval.
This vulnerability aligns with CWE-284, which describes improper access control, and relates to ATT&CK technique T1595.001 for reconnaissance through scanning tools. Organizations using GitLab should immediately upgrade to version 12.3.3 or later to remediate this issue, as the fix addresses the underlying access control logic within the merge request widget. Additional mitigations include reviewing project-level pipeline settings to ensure public access is properly restricted, implementing network-level controls to limit access to GitLab instances, and monitoring for unusual access patterns in scanning report queries. The vulnerability underscores the importance of comprehensive access control testing and the need for security validation across all user interface components, particularly those that aggregate and display sensitive project information.