CVE-2021-22201 in Community Edition
Summary
by MITRE • 04/02/2021
An issue has been discovered in GitLab CE/EE affecting all versions starting from 13.9. A specially crafted import file could read files on the server.
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Analysis
by VulDB Data Team • 08/21/2024
The vulnerability identified as CVE-2021-22201 represents a critical server-side file reading flaw within GitLab Community and Enterprise editions. This security weakness affects all versions beginning with 13.9 and stems from inadequate input validation during the import process. The vulnerability allows remote attackers to craft malicious import files that can traverse the file system and read arbitrary files on the GitLab server hosting the vulnerable instance. Such a flaw fundamentally compromises the integrity of the system's file access controls and represents a severe privilege escalation vector.
The technical implementation of this vulnerability resides in the import functionality that processes external files into GitLab repositories. When users attempt to import project data from external sources, the system fails to properly sanitize file paths or validate the contents of imported files. This lack of proper validation creates a path traversal condition where attacker-controlled input can manipulate the file system access mechanisms. The flaw operates at the application layer and can be exploited without authentication, making it particularly dangerous in environments where GitLab instances are exposed to untrusted users or external networks. This vulnerability directly maps to CWE-22 Path Traversal and aligns with ATT&CK technique T1059.007 Command and Scripting Interpreter for file system manipulation.
The operational impact of CVE-2021-22201 extends far beyond simple data theft, as it can provide attackers with access to sensitive system files including configuration files, database credentials, and potentially system-level information. In a typical GitLab deployment, this vulnerability could expose database connection strings, API keys, private SSH keys, and other confidential information stored within the server's file system. The implications are particularly severe in containerized environments or cloud deployments where GitLab instances may have access to broader infrastructure resources. Organizations running vulnerable GitLab instances face significant risk of data breaches, system compromise, and potential lateral movement within their network infrastructure.
Organizations should immediately upgrade to GitLab version 13.10.3 or later, which contains the necessary patches to address this vulnerability. The fix implements proper input validation and sanitization of file paths during the import process, preventing malicious path traversal attempts. Additionally, administrators should review and restrict import permissions to trusted users only, implement network segmentation to limit access to GitLab instances, and monitor for suspicious import activities. Security teams should also consider implementing web application firewalls and intrusion detection systems to detect potential exploitation attempts. Regular security audits of GitLab configurations and access controls remain essential to maintaining a secure deployment environment. The vulnerability serves as a reminder of the critical importance of input validation in web applications and the potential consequences of insufficient sanitization of user-provided data in file system operations.