CVE-2018-8971 in GitLab
Summary
by MITRE
The Auth0 integration in GitLab before 10.3.9, 10.4.x before 10.4.6, and 10.5.x before 10.5.6 has an incorrect omniauth-auth0 configuration, leading to signing in unintended users.
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Analysis
by VulDB Data Team • 01/16/2020
The vulnerability identified as CVE-2018-8971 represents a critical authentication flaw within GitLab's integration with Auth0 identity management service. This issue affects multiple versions of GitLab including releases prior to 10.3.9, 10.4.x prior to 10.4.6, and 10.5.x prior to 10.5.6, creating a significant security risk for organizations relying on this authentication mechanism. The flaw stems from an improper configuration of the omniauth-auth0 integration that allows unauthorized users to gain access to systems they should not be permitted to access. This misconfiguration essentially undermines the intended authentication controls and creates a backdoor for potential attackers to bypass normal access restrictions.
The technical nature of this vulnerability can be categorized under CWE-287 which addresses improper authentication issues, specifically focusing on authentication bypass through flawed configuration management. The root cause lies in how GitLab handled the omniauth-auth0 integration where the configuration parameters were not properly validated or secured, leading to a scenario where authentication tokens or user credentials could be manipulated or exploited by unauthorized parties. This misconfiguration creates an environment where legitimate users may be denied access while unauthorized individuals can potentially authenticate successfully, fundamentally compromising the security posture of the affected systems.
From an operational perspective, this vulnerability poses severe risks to organizations using GitLab's continuous integration and deployment platforms. The impact extends beyond simple unauthorized access to include potential data breaches, privilege escalation, and unauthorized modifications to code repositories and infrastructure configurations. Attackers could exploit this flaw to gain access to sensitive source code, deployment credentials, and other critical system resources that should remain protected. The vulnerability particularly affects DevOps environments where GitLab serves as a central hub for development workflows, making it a prime target for attackers seeking to compromise development pipelines and steal intellectual property.
Organizations should immediately implement mitigations including upgrading to the patched versions of GitLab as specified in the CVE advisory, which addresses the improper omniauth-auth0 configuration. Security administrators must also review and validate all authentication configurations within their GitLab instances, ensuring that identity provider integrations are properly secured and validated. Additional defensive measures include implementing multi-factor authentication for administrative accounts, monitoring authentication logs for suspicious activities, and conducting regular security assessments of third-party integrations. The ATT&CK framework categorizes this vulnerability under privilege escalation and initial access techniques, emphasizing the need for comprehensive security controls that address both authentication configuration weaknesses and broader access control mechanisms. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of such vulnerabilities within their overall security architecture.