CVE-2019-5468 in Community Edition
Summary
by MITRE
An privilege escalation issue was discovered in Gitlab versions < 12.1.2, < 12.0.4, and < 11.11.6 when Mattermost slash commands are used with a blocked account.
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Analysis
by VulDB Data Team • 03/27/2024
The vulnerability identified as CVE-2019-5468 represents a critical privilege escalation flaw within GitLab's integration with Mattermost slash commands. This security issue specifically affects GitLab versions prior to 12.1.2, 12.0.4, and 11.11.6, creating a significant risk for organizations relying on these platforms for collaborative development and communication. The flaw manifests when Mattermost slash commands are executed against blocked user accounts, allowing unauthorized individuals to exploit the system's access controls and elevate their privileges beyond normal boundaries.
The technical implementation of this vulnerability stems from inadequate input validation and access control mechanisms within GitLab's Mattermost integration module. When slash commands are processed through the integrated Mattermost system, the application fails to properly verify whether the target user account has been blocked or restricted. This oversight creates a pathway where malicious actors can manipulate command execution flows to bypass normal authentication and authorization checks. The vulnerability operates at the intersection of user management and command processing, where blocked accounts should not be accessible to commands but are still being processed with elevated permissions. This flaw aligns with CWE-284, which addresses improper access control issues, and demonstrates how integration points between different systems can create unexpected security gaps.
The operational impact of CVE-2019-5468 extends beyond simple privilege escalation, potentially enabling attackers to gain unauthorized access to sensitive project data, manipulate repository contents, and compromise the integrity of development workflows. Organizations utilizing GitLab with Mattermost integrations face significant risk of data breaches, unauthorized code modifications, and potential lateral movement within their development environments. The vulnerability is particularly dangerous because it can be exploited without requiring direct system access or advanced technical skills, making it attractive to threat actors seeking to compromise development environments. Attackers could leverage this flaw to execute commands that would normally be restricted to administrators or project owners, potentially leading to complete system compromise.
Mitigation strategies for CVE-2019-5468 require immediate implementation of the vendor-provided security patches and updates for GitLab versions 12.1.2, 12.0.4, and 11.11.6. Organizations should also implement additional monitoring and logging of slash command executions, particularly those targeting blocked user accounts. Network segmentation and access control policies should be reviewed to minimize the potential impact of privilege escalation attempts. Security teams should conduct thorough assessments of their Mattermost integration configurations and implement proper input sanitization measures. From an ATT&CK framework perspective, this vulnerability relates to privilege escalation techniques and can be categorized under T1068, which covers local privilege escalation, and T1566, which addresses credential harvesting. Organizations should also consider implementing behavioral analytics to detect anomalous command execution patterns that might indicate exploitation attempts. The remediation process should include comprehensive testing of patched environments to ensure that the vulnerability has been properly addressed without introducing regressions in functionality.