CVE-2016-9469 in GitLab
Summary
by MITRE
Multiple versions of GitLab expose a dangerous method to any authenticated user that could lead to the deletion of all Issue and MergeRequest objects on a GitLab instance. For GitLab instances with publicly available projects this vulnerability could be exploited by an unauthenticated user. A fix was included in versions 8.14.3, 8.13.8, and 8.12.11, which were released on December 5th 2016 at 3:59 PST. The GitLab versions vulnerable to this are 8.13.0, 8.13.0-ee, 8.13.1, 8.13.1-ee, 8.13.2, 8.13.2-ee, 8.13.3, 8.13.3-ee, 8.13.4, 8.13.4-ee, 8.13.5, 8.13.5-ee, 8.13.6, 8.13.6-ee, 8.13.7, 8.14.0, 8.14.0-ee, 8.14.1, 8.14.2, and 8.14.2-ee.
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Analysis
by VulDB Data Team • 11/22/2022
This vulnerability represents a critical access control flaw in GitLab's issue and merge request management system that allows authenticated users to execute destructive operations on project data. The flaw stems from a dangerous method exposed through GitLab's API that enables users to delete all issue and merge request objects within a GitLab instance. The vulnerability's severity is amplified by its accessibility to unauthenticated users when public projects are enabled, making it a particularly dangerous exposure for organizations with open repositories. The affected versions span multiple release lines including 8.13.x and 8.14.x, indicating this was a widespread issue affecting the core functionality of GitLab's project management features.
The technical implementation of this vulnerability involves a method that bypasses proper authorization checks for issue and merge request deletion operations. This flaw operates under the principle of insufficient authorization, which maps directly to CWE-285, where the system fails to properly verify that the requesting user has sufficient privileges to perform the requested operation. The vulnerability exists because GitLab's API endpoints for managing issues and merge requests did not adequately validate user permissions or implement proper access controls before executing destructive operations. This type of flaw is particularly concerning in collaborative development environments where multiple users may have varying levels of access rights.
The operational impact of this vulnerability extends far beyond simple data loss, as it represents a complete breakdown in project management integrity within GitLab instances. An attacker exploiting this vulnerability could potentially destroy all issue tracking and merge request data, effectively compromising the entire development workflow tracking system. For organizations relying on GitLab for code review processes, bug tracking, and project coordination, this vulnerability would result in complete loss of historical development context and collaboration data. The damage could be catastrophic for teams that depend on the audit trail provided by issue and merge request systems, as all previous work tracking and discussion would be permanently deleted. This vulnerability also creates potential for denial of service conditions where legitimate users cannot access their project management data.
The exploitation of this vulnerability requires minimal privileges for authenticated users, making it particularly dangerous as it can be leveraged by insiders or compromised accounts. For public project environments, unauthenticated attackers could potentially exploit this through the same API endpoints, making it a zero-day threat for organizations with open repositories. The vulnerability's presence in multiple versions across different release lines indicates that GitLab's access control mechanisms were fundamentally flawed in the affected versions, requiring a complete redesign of the authorization logic for issue and merge request operations. Organizations using vulnerable versions would have been at risk for several months, as the vulnerability existed in a range of stable releases that many organizations would have been running in production environments.
The fix implemented by GitLab in versions 8.14.3, 8.13.8, and 8.12.11 addressed the core authorization bypass by strengthening access control validation for issue and merge request operations. This remediation aligns with the ATT&CK framework's privilege escalation techniques, where attackers exploit authorization flaws to gain elevated access to system resources. The fix demonstrates the importance of proper input validation and access control implementation in web applications, particularly those handling collaborative development data. Organizations should implement comprehensive monitoring of API access patterns and user activities to detect potential exploitation attempts, as the vulnerability would likely generate unusual patterns of issue and merge request deletions. The incident highlights the critical need for regular security assessments of development platform components and the importance of maintaining up-to-date software versions to protect against known vulnerabilities.