CVE-2019-18449 in Community Edition
Summary
by MITRE
An issue was discovered in GitLab Community and Enterprise Edition before 12.4 in the autocomplete feature. It has Insecure Permissions (issue 2 of 2).
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Analysis
by VulDB Data Team • 02/28/2024
The vulnerability identified as CVE-2019-18449 represents a critical insecure permissions flaw within GitLab's autocomplete functionality affecting versions prior to 12.4. This issue resides in the community and enterprise editions of the GitLab platform, where the autocomplete feature fails to properly enforce access controls and authorization checks. The flaw manifests as a privilege escalation vulnerability that allows authenticated users to access sensitive data and functionality beyond their intended permissions. The vulnerability specifically impacts the autocomplete feature which is commonly used for project name suggestions, user name suggestions, and other similar functionality within the GitLab interface. This represents a fundamental breakdown in the platform's access control mechanisms where the system does not adequately validate user permissions before providing autocomplete suggestions.
The technical implementation of this vulnerability stems from inadequate input validation and permission checking within the autocomplete endpoint. When users interact with the autocomplete functionality, the system should verify that the requesting user has appropriate access rights to view the suggested items. However, the flaw allows unauthorized access to project data, user information, and potentially sensitive repository details through the autocomplete suggestions. This occurs because the autocomplete service does not properly filter results based on user roles, project memberships, or access levels. The vulnerability is particularly concerning as it operates silently in the background, potentially exposing confidential information to users who should not have access to such data. The flaw aligns with CWE-284 which specifically addresses inadequate access control and improper privilege management in software systems.
The operational impact of CVE-2019-18449 extends beyond simple information disclosure to potentially enable more sophisticated attacks within the GitLab environment. An attacker with basic user credentials could leverage this vulnerability to discover the existence of private projects, identify team members, and gather intelligence about the organization's repository structure. This reconnaissance capability could facilitate further attacks such as privilege escalation attempts, social engineering campaigns, or targeted exploitation of other vulnerabilities. The vulnerability affects both community and enterprise editions, making it a widespread concern across different GitLab deployment models. Organizations using older versions of GitLab are particularly at risk as the flaw remains exploitable until the patch is applied, potentially allowing persistent unauthorized access to sensitive information.
Security mitigations for this vulnerability require immediate patching of GitLab installations to version 12.4 or later where the autocomplete permissions have been properly addressed. Organizations should also implement network segmentation and access controls to limit exposure of GitLab instances to unauthorized users. Additional monitoring should be implemented to detect unusual autocomplete usage patterns that might indicate exploitation attempts. The fix typically involves strengthening permission validation within the autocomplete service to ensure that suggestions are filtered according to user access levels and project memberships. From an ATT&CK perspective, this vulnerability maps to techniques involving privilege escalation and reconnaissance, as attackers can use the autocomplete feature to gather intelligence about the target environment. Regular security assessments and vulnerability scanning should be conducted to identify similar permission-related issues in other applications and services within the organization's infrastructure.