CVE-2021-22215 in Enterprise Edition
Summary
by MITRE • 06/08/2021
An information disclosure vulnerability in GitLab EE versions 13.11 and later allowed a project owner to leak information about the members' on-call rotations in other projects
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Analysis
by VulDB Data Team • 06/11/2021
This vulnerability represents a critical information disclosure flaw in GitLab Enterprise Edition that emerged in versions 13.11 and later. The issue stems from insufficient access controls within the on-call rotation functionality, allowing unauthorized users to access sensitive information about team members' scheduled duties across different projects. The vulnerability specifically affects project owners who can exploit a design flaw in the API endpoints responsible for retrieving on-call rotation data. This represents a direct violation of the principle of least privilege and demonstrates a failure in access control mechanisms that should prevent cross-project information leakage.
The technical implementation of this vulnerability involves a path traversal or improper access control pattern where the system fails to properly validate user permissions when accessing on-call rotation information. Attackers with project owner privileges can craft specific API requests that bypass normal access restrictions, enabling them to enumerate and retrieve on-call schedules from projects they should not have access to. This flaw operates at the application layer and can be exploited through the GitLab API without requiring elevated system privileges. The vulnerability aligns with CWE-284 Access Control Issues, specifically targeting improper access control mechanisms that allow unauthorized information disclosure.
The operational impact of this vulnerability extends beyond simple information leakage, as it can compromise team security and operational effectiveness. When project owners can access on-call rotation data from other projects, they gain insight into team member schedules, responsibilities, and potential security gaps in different project contexts. This information can be leveraged for social engineering attacks, targeted phishing campaigns, or to identify potential attack vectors where team members are most vulnerable. The exposure of on-call schedules may also violate privacy policies and data protection regulations, particularly in environments where such information is considered sensitive personnel data. This vulnerability directly relates to ATT&CK technique T1082 Discovery of System Information and T1566 Impersonation, as it enables unauthorized discovery and potential exploitation of system resources.
Organizations should implement immediate mitigations including applying the latest GitLab security patches, reviewing and tightening access control policies for on-call rotation features, and monitoring API access logs for suspicious activity. System administrators should also consider implementing additional network segmentation and access controls around sensitive API endpoints. The vulnerability highlights the importance of regular security assessments and proper input validation in web applications. Organizations should conduct comprehensive reviews of their GitLab configurations and ensure that all users have appropriate access levels based on their actual project needs rather than elevated privileges that could enable information leakage. Regular security training for developers and administrators on secure coding practices and access control implementation remains critical to preventing similar vulnerabilities in the future.