CVE-2020-5197 in Community Edition
Summary
by MITRE
An issue was discovered in GitLab Community Edition (CE) and Enterprise Edition (EE) 5.1 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-2020-5197 represents a critical access control flaw affecting GitLab Community Edition and Enterprise Edition versions ranging from 5.1 through 12.6.1. This issue stems from inadequate authorization mechanisms that allow unauthorized users to access protected resources within the GitLab platform. The flaw specifically manifests in how the system validates user permissions when accessing certain project-related functionalities, creating a pathway for privilege escalation and unauthorized data access. Security researchers identified that authenticated users could exploit this vulnerability to gain access to private repositories and project data that should be restricted to authorized personnel only, fundamentally undermining the core security model of the GitLab platform.
The technical implementation of this access control vulnerability occurs at the application layer where GitLab fails to properly validate user permissions during specific API calls and web interface interactions. The flaw exists in the permission checking logic that governs access to project resources, particularly affecting scenarios where users attempt to access project-level data through various API endpoints. Attackers can leverage this weakness by crafting specific requests that bypass normal authorization checks, potentially gaining read access to private repositories, project settings, and sensitive code artifacts. This type of vulnerability falls under the CWE-284 category of Improper Access Control, which specifically addresses insufficient access control mechanisms that allow unauthorized users to access protected resources. The vulnerability demonstrates a classic lack of proper input validation and authorization enforcement that violates fundamental security principles.
The operational impact of CVE-2020-5197 extends beyond simple data exposure, potentially enabling attackers to compromise entire development environments and sensitive intellectual property. Organizations using affected GitLab versions face significant risks including unauthorized code access, potential data exfiltration, and the possibility of further attacks leveraging compromised repository access. The vulnerability affects both community and enterprise editions, meaning that the risk is widespread across the GitLab user base. Attackers could exploit this flaw to access confidential source code, configuration files, and other sensitive project artifacts that may contain credentials, API keys, or other security-sensitive information. The implications are particularly severe for organizations that rely heavily on GitLab for version control and collaboration, as the compromise of a single repository could expose multiple projects and development workflows.
Mitigation strategies for CVE-2020-5197 primarily focus on immediate version upgrades to patched releases of GitLab, specifically versions 12.7.0 and later where the access control mechanisms have been properly implemented. Organizations should also implement network-level controls and monitoring to detect anomalous access patterns that might indicate exploitation attempts. Security teams should conduct comprehensive audits of their GitLab installations to identify any unauthorized access that may have occurred during the vulnerability window. Additional defensive measures include implementing multi-factor authentication, regularly reviewing user permissions, and establishing strict access control policies for sensitive repositories. The vulnerability highlights the importance of maintaining up-to-date security patches and demonstrates how seemingly minor access control flaws can result in significant security breaches. Organizations should also consider implementing security monitoring solutions that can detect and alert on unusual GitLab API access patterns that might indicate exploitation attempts. This vulnerability serves as a reminder of the critical importance of proper access control implementation and the need for continuous security testing and validation of authorization mechanisms.