CVE-2019-18451 in Community Edition
Summary
by MITRE
An issue was discovered in GitLab Community and Enterprise Edition 10.7.4 through 12.4 in the InternalRedirect filtering feature. It has an Open Redirect.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 02/28/2024
The vulnerability identified as CVE-2019-18451 represents a critical security flaw in GitLab's InternalRedirect filtering mechanism affecting versions 10.7.4 through 12.4 of both Community and Enterprise editions. This issue stems from inadequate input validation within GitLab's redirect handling functionality, creating a pathway for malicious actors to manipulate redirect URLs. The flaw allows unauthorized redirection to arbitrary external domains, potentially enabling phishing attacks and social engineering campaigns that could compromise user credentials or system integrity. The vulnerability specifically affects the internal redirect filtering feature that is designed to prevent unauthorized redirection but instead fails to properly validate or sanitize redirect destinations.
The technical implementation of this vulnerability resides in GitLab's handling of redirect parameters within its web application framework. When users interact with GitLab's authentication or navigation features, the system processes redirect URLs that should be validated against a whitelist of approved domains. However, the filtering mechanism contains a logic flaw that permits certain malicious URLs to bypass validation checks, effectively allowing attackers to craft redirect URLs that point to attacker-controlled domains. This represents a classic open redirect vulnerability where the application fails to properly validate redirect destinations, enabling attackers to redirect users from trusted GitLab domains to malicious external sites.
The operational impact of CVE-2019-18451 extends beyond simple redirection attacks to encompass broader security implications for organizations using GitLab platforms. Attackers could leverage this vulnerability to conduct phishing campaigns by redirecting users to fake login pages that mimic GitLab's interface, potentially capturing authentication credentials. The vulnerability also enables more sophisticated attacks such as credential harvesting, session hijacking, and malware distribution through malicious redirects. Organizations relying on GitLab for code repository management, CI/CD pipelines, and collaboration could face significant risks including data exfiltration, unauthorized code modifications, and compromise of development environments. The attack surface is particularly concerning given GitLab's widespread adoption across enterprise environments where developers frequently interact with the platform.
Mitigation strategies for CVE-2019-18451 should prioritize immediate patching of affected GitLab installations to versions that address the redirect filtering flaw. Organizations should implement network-level controls and web application firewalls to monitor and block suspicious redirect patterns, though this represents a secondary defense measure. Security teams should conduct comprehensive audits of GitLab configurations to ensure proper redirect validation is enabled and maintained. The vulnerability aligns with CWE-601 Open Redirect vulnerability classification and maps to ATT&CK technique T1566.001 Phishing, where attackers exploit redirect mechanisms to deliver malicious payloads. Additionally, organizations should implement user education programs to raise awareness about suspicious redirects and establish monitoring procedures to detect anomalous redirect behavior in their GitLab environments. Regular security assessments of web applications and proper input validation practices should be enforced to prevent similar vulnerabilities from emerging in other components of the software ecosystem.