CVE-2023-4658 : Security Advisory and Response

An issue of improper access control has been discovered in GitLab, affecting various versions. This vulnerability could allow an attacker to exploit the

Allowed to merge

permission as a guest user, particularly when granted through a group.

Understanding CVE-2023-4658

This section delves into the details of CVE-2023-4658, outlining its impact, technical description, affected systems, exploitation mechanism, mitigation, and prevention techniques.

What is CVE-2023-4658?

CVE-2023-4658 is an improper access control vulnerability in GitLab EE, impacting versions ranging from 8.13 to specific versions before 16.4.3, 16.5.3, and 16.6.1. The vulnerability revolves around the abuse of the

Allowed to merge

permission by an attacker with guest user privileges when granted via a group.

The Impact of CVE-2023-4658

The vulnerability poses a low severity risk (CVSS base score of 3.1) to affected systems. If exploited, an attacker could potentially bypass access controls and carry out unauthorized actions within GitLab, compromising the integrity of data.

Technical Details of CVE-2023-4658

This section provides a deeper dive into the technical aspects of CVE-2023-4658, including a description of the vulnerability, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability arises from improper access control mechanisms in GitLab, specifically within the

Allowed to merge

permission functionality. Attackers leveraging this flaw could manipulate the permission settings granted to guest users via groups.

Affected Systems and Versions

GitLab versions 8.13 to versions prior to 16.4.3, 16.5.3, and 16.6.1 are impacted by this vulnerability. Organizations using these versions may be susceptible to exploitation if the access control issue is not addressed promptly.

Exploitation Mechanism

Exploiting CVE-2023-4658 entails an attacker with guest user permissions abusing the

Allowed to merge

capability received through a group, bypassing intended access controls and carrying out unauthorized activities within GitLab.

Mitigation and Prevention

In response to CVE-2023-4658, GitLab has recommended several steps to mitigate the risk associated with this vulnerability, focusing on immediate actions and long-term security practices.

Immediate Steps to Take

Organizations using affected GitLab versions should promptly upgrade to versions 16.4.3, 16.5.3, 16.6.1, or newer to mitigate the vulnerability and prevent potential exploitation.

Long-Term Security Practices

To enhance overall security posture, organizations are advised to prioritize access control configurations, ensure proper permissions management, and conduct regular security audits to identify and address any potential vulnerabilities proactively.

Patching and Updates

Regularly applying patches and updates released by GitLab is crucial to maintaining the security and integrity of the platform. Staying current with the latest versions helps organizations stay protected against known vulnerabilities and exploits.