CVE-2019-20147 in Community Edition
Summary
by MITRE
An issue was discovered in GitLab Community Edition (CE) and Enterprise Edition (EE) 9.1 through 12.6.1. It has Incorrect Access Control.
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Analysis
by VulDB Data Team • 01/14/2020
The vulnerability identified as CVE-2019-20147 represents a critical access control flaw affecting GitLab Community Edition and Enterprise Edition versions ranging from 9.1 through 12.6.1. This issue stems from insufficient authorization checks within the GitLab platform's permission system, creating a scenario where authenticated users can potentially access restricted resources and functionality that should only be available to administrators or authorized personnel. The flaw exists in the application's core access control mechanisms, specifically within how the system validates user permissions for various operations and resource access. Security researchers discovered that the vulnerability allows for privilege escalation through improper validation of user roles and access levels, enabling malicious actors to bypass intended security boundaries.
The technical implementation of this access control failure manifests in the way GitLab handles user authentication tokens and session validation during various API calls and web interface interactions. The vulnerability occurs when the system fails to properly verify whether a user possesses the necessary permissions to access specific project resources or administrative functions. This weakness is particularly concerning because it affects the fundamental security model of the platform, where users with legitimate access can exploit this flaw to gain unauthorized access to sensitive project data, configuration settings, and administrative controls. The flaw operates at the application layer, specifically within the authentication and authorization modules that govern user access rights across different GitLab components and features.
The operational impact of CVE-2019-20147 extends beyond simple data exposure, as it fundamentally undermines the security posture of GitLab installations. Organizations utilizing affected versions face potential risks including unauthorized code access, project manipulation, data leakage, and possible system compromise through privilege escalation. Attackers could leverage this vulnerability to access confidential source code repositories, modify project configurations, manipulate user permissions, or even gain administrative control over entire GitLab instances. The vulnerability affects both community and enterprise editions, meaning that organizations across different licensing tiers are equally at risk, potentially leading to widespread security breaches across development environments that rely on GitLab for version control and collaboration. This access control failure creates a persistent threat vector that could remain undetected for extended periods, as legitimate users may not immediately recognize unauthorized access to their systems.
Organizations should immediately implement mitigations including updating to GitLab versions that have patched this vulnerability, specifically versions 12.7.2 and later for the 12.7 release, or 12.6.2 and later for the 12.6 release. System administrators should conduct comprehensive access control reviews and implement additional monitoring for unauthorized access attempts. The vulnerability aligns with CWE-284, which addresses improper access control, and maps to ATT&CK technique T1078 for valid accounts and privilege escalation. Security teams should also consider implementing network segmentation, enhanced logging, and regular security audits to detect potential exploitation attempts. Additionally, organizations should review their existing user permission configurations and ensure that least privilege principles are properly enforced throughout their GitLab deployments.