CVE-2019-10116 in Community Edition
Summary
by MITRE
An Insecure Permissions issue (issue 3 of 3) was discovered in GitLab Community and Enterprise Edition before 11.7.8, 11.8.x before 11.8.4, and 11.9.x before 11.9.2. Guests of a project were allowed to see Related Branches created for an issue.
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Analysis
by VulDB Data Team • 09/21/2023
The vulnerability identified as CVE-2019-10116 represents a critical access control flaw in GitLab's permission model that affected multiple versions of the GitLab Community and Enterprise Edition platforms. This issue falls under the broader category of insecure permissions problems that can compromise the integrity of access controls within software systems. The vulnerability specifically impacts GitLab installations running versions prior to 11.7.8, 11.8.4, and 11.9.2 respectively, creating a window of exposure for organizations relying on these older versions. The flaw manifests when guest users, who typically have limited access rights, are able to view related branches that were created specifically for issue tracking purposes within project environments.
The technical implementation of this vulnerability stems from insufficient authorization checks within GitLab's branch visibility mechanisms. When issues are created within GitLab projects, the system often generates related branches to facilitate development work and issue resolution. These branches typically contain sensitive information related to the specific issue being addressed, including code changes, development notes, and implementation details. The flaw occurs because guest users who should only have read access to project files and basic issue tracking information are granted access to these related branches, effectively bypassing the intended permission boundaries. This represents a clear violation of the principle of least privilege, where users should only have access to resources necessary for their specific role within the project.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can lead to unauthorized access to potentially sensitive development information. Guest users who gain access to related branches may inadvertently or intentionally access code modifications, development strategies, or implementation details that were not intended for their level of access. This could expose organizations to intellectual property risks, reveal development timelines and strategies, or provide insights into system vulnerabilities that could be exploited by malicious actors. The vulnerability is particularly concerning in enterprise environments where projects may contain proprietary code, security-sensitive implementations, or business-critical development work that should remain restricted to authorized personnel.
Organizations affected by this vulnerability should prioritize immediate remediation through version upgrades to GitLab 11.7.8, 11.8.4, or 11.9.2, depending on their current installation version. The fix implemented by GitLab addresses the underlying permission checking mechanism to ensure that guest users cannot access related branches created for specific issues, maintaining proper separation between different user roles and access levels. This vulnerability aligns with CWE-284, which describes improper access control issues, and could potentially be leveraged as part of a broader attack chain where initial access through such permission flaws leads to more severe compromises. Security teams should also consider implementing additional monitoring to detect unusual access patterns that might indicate exploitation attempts, and should review their overall access control policies to ensure that similar issues do not exist in other components of their software development infrastructure. The ATT&CK framework would classify this as a privilege escalation technique, as it allows lower-privileged users to gain access to resources that should be restricted to higher-privileged roles within the system.