CVE-2023-5600 in Enterprise Edition
Summary
by MITRE • 06/20/2025
An issue has been discovered in GitLab EE affecting all versions starting from 16.0 before 16.3.6, all versions starting from 16.4 before 16.4.2, all versions starting from 16.5 before 16.5.1. Arbitrary access to the titles of an private specific references could be leaked through the service-desk custom email template.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 06/21/2025
The vulnerability identified as CVE-2023-5600 represents a critical information disclosure flaw within GitLab Enterprise Edition that affects multiple version ranges including 16.0 through 16.3.5, 16.4 through 16.4.1, and 16.5 through 16.5.0. This issue specifically targets the service-desk functionality and allows unauthorized access to private reference titles through custom email templates, creating a significant security risk for organizations relying on GitLab for their code management and collaboration needs. The flaw exists in the way GitLab handles email template processing for service desk requests, where the system fails to properly validate access controls when rendering custom email templates that reference private objects within the repository.
The technical implementation of this vulnerability stems from inadequate input validation and access control mechanisms within GitLab's service-desk email template processing subsystem. When administrators configure custom email templates for service desk functionality, the system should enforce proper authentication and authorization checks to ensure that only authorized users can access private reference data. However, the flaw allows attackers to manipulate the email template rendering process to extract titles of private references without proper authorization. This type of vulnerability aligns with CWE-200, which describes improper output sanitization or information exposure, and specifically relates to CWE-668, which covers insufficient control of a resource through access control mechanisms. The vulnerability operates through a path traversal or information disclosure pattern that bypasses normal access control boundaries, allowing unauthorized data retrieval through the email template system.
The operational impact of CVE-2023-5600 extends beyond simple information disclosure as it potentially exposes sensitive project metadata and reference titles that could aid in further attack planning. Attackers could leverage this vulnerability to gather intelligence about private repositories, identify sensitive project structures, and potentially discover other vulnerabilities within the system. The exposure of private reference titles could provide attackers with insights into project naming conventions, development practices, and internal organizational structures. This vulnerability particularly affects organizations that rely heavily on GitLab's service desk functionality for customer support and issue tracking, as it creates a potential attack vector that could be exploited to gather information about private projects. The risk is amplified when considering that service desk functionality often handles sensitive customer data and project information that should remain confidential.
Organizations should implement immediate mitigations including upgrading to the patched versions of GitLab Enterprise Edition 16.3.6, 16.4.2, or 16.5.1 respectively, which contain the necessary fixes for this vulnerability. System administrators should also review and audit existing service desk email templates to ensure no custom configurations are exposing private reference data. The mitigation strategy should include implementing proper access control validation for all email template processing and ensuring that custom templates do not reference private objects without proper authentication checks. From an ATT&CK framework perspective, this vulnerability maps to T1213.002, which covers data from information repositories, and T1566.002, which involves spearphishing with social engineering. Organizations should also consider implementing network monitoring to detect potential exploitation attempts and establish incident response procedures specifically addressing information disclosure vulnerabilities in collaboration platforms. The vulnerability highlights the importance of proper access control implementation in web applications and the need for comprehensive security testing of email template processing functionality.