CVE-2024-0456 in GitLab
Summary
by MITRE • 01/26/2024
An authorization vulnerability exists in GitLab versions 14.0 prior to 16.6.6, 16.7 prior to 16.7.4, and 16.8 prior to 16.8.1. An unauthorized attacker is able to assign arbitrary users to MRs that they created within the project
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 10/03/2024
This authorization vulnerability in GitLab represents a critical access control flaw that allows unauthorized users to manipulate merge requests they have created. The vulnerability stems from insufficient validation of user permissions during merge request assignment operations, enabling attackers to bypass normal access controls and assign MRs to other users or groups. The flaw affects multiple version ranges including 14.0 through 16.6.5, 16.7 through 16.7.3, and 16.8 through 16.8.0, indicating a prolonged period where the authorization mechanism was compromised. This issue falls under CWE-285, which specifically addresses improper authorization within software systems, making it a direct violation of fundamental security principles. The vulnerability aligns with ATT&CK technique T1078.004 which covers valid accounts used for lateral movement, as attackers could exploit this to gain control over MR assignments and potentially manipulate code review processes.
The technical implementation of this flaw occurs during the merge request assignment workflow where the system fails to properly verify whether the requesting user has sufficient privileges to assign MRs to other users. When an attacker creates a merge request and subsequently attempts to assign it to another user, the authorization check is bypassed, allowing arbitrary assignment. This creates a scenario where malicious actors can manipulate the ownership and visibility of MRs, potentially enabling them to circumvent code review processes, inject malicious code, or disrupt normal development workflows. The vulnerability is particularly concerning because merge requests are central to GitLab's code collaboration and review processes, making this a high-impact security issue.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can be exploited to manipulate the entire code review and merge process. Attackers could assign MRs to users with elevated privileges, potentially gaining unauthorized access to sensitive code branches or triggering privilege escalation scenarios. The vulnerability also enables social engineering attacks where malicious users could assign MRs to unsuspecting team members, causing confusion and potential security incidents. Additionally, this flaw can be leveraged to disrupt development workflows by manipulating MR assignment status, creating audit trail inconsistencies, and potentially enabling denial of service scenarios. Organizations using GitLab in production environments face significant risks including potential code injection, unauthorized access to sensitive repositories, and compromised development integrity.
The recommended mitigation strategy involves upgrading to the patched versions of GitLab where this authorization flaw has been addressed. Organizations should immediately implement the security updates for versions 16.6.6, 16.7.4, and 16.8.1 respectively. In addition to patching, administrators should conduct thorough access control reviews and monitor MR assignment activities for any suspicious patterns. The vulnerability highlights the importance of proper input validation and authorization checks in collaborative development platforms, emphasizing the need for comprehensive security testing of access control mechanisms. Organizations should also consider implementing additional monitoring solutions that can detect anomalous MR assignment behaviors and establish incident response procedures specifically tailored to address such authorization bypass scenarios.