CVE-2023-6736 in Enterprise Edition
Summary
by MITRE • 02/08/2024
An issue has been discovered in GitLab EE affecting all versions starting from 11.3 before 16.6.7, all versions starting from 16.7 before 16.7.5, all versions starting from 16.8 before 16.8.2. It was possible for an attacker to cause a client-side denial of service using malicious crafted content in the CODEOWNERS file.
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Analysis
by VulDB Data Team • 10/03/2024
The vulnerability identified as CVE-2023-6736 represents a client-side denial of service flaw within GitLab Enterprise Edition that has persisted across multiple version ranges including 11.3 through 16.6.6, 16.7 through 16.7.4, and 16.8 through 16.8.1. This issue specifically targets the CODEOWNERS file processing functionality, which is a critical component in GitLab's repository management system that defines which users or groups are responsible for specific files or directories. The vulnerability stems from insufficient input validation and sanitization when parsing maliciously crafted content within these files, creating an exploitable condition that can be leveraged by remote attackers to disrupt client-side operations.
The technical implementation of this vulnerability involves the improper handling of specially crafted content within CODEOWNERS files that can trigger unexpected behavior in the GitLab web interface or client applications. When a user accesses a repository containing such malicious content, the parsing mechanism fails to properly validate the input, leading to resource exhaustion or execution errors that result in service disruption. This flaw operates at the application layer and specifically affects the client-side rendering components that process and display CODEOWNERS information to users. The vulnerability is classified under CWE-400 as an Uncontrolled Resource Consumption, which aligns with the denial of service characteristics exhibited by this flaw. The attack vector requires minimal privileges as it can be exploited through repository content manipulation without requiring authentication or administrative access to the GitLab instance itself.
The operational impact of CVE-2023-6736 extends beyond simple service disruption to potentially affecting user productivity and collaboration workflows within GitLab environments. When exploited, this vulnerability can cause web browsers or client applications to freeze, crash, or become unresponsive when attempting to view repositories containing malicious CODEOWNERS content. This affects not only individual users but can also impact entire development teams working within affected repositories, particularly in environments where CODEOWNERS files are extensively used for access control and code review processes. The vulnerability's persistence across multiple major version releases indicates a fundamental flaw in the input validation logic that requires immediate attention. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 as a Network Denial of Service, where the attacker leverages a weakness in the application's resource management to exhaust client-side resources, and T1566.001 as a Phishing with Malicious File, where the attack is delivered through seemingly legitimate repository files.
Organizations affected by CVE-2023-6736 should implement immediate mitigation strategies including updating to the patched versions 16.6.7, 16.7.5, and 16.8.2 respectively, while also establishing content validation procedures for CODEOWNERS files in their repository management policies. Administrators should consider implementing automated scanning tools to detect potentially malicious content in repository files before they can be exploited, and should educate development teams about the risks associated with untrusted CODEOWNERS content. The vulnerability demonstrates the importance of robust input validation in web applications and highlights the need for continuous security testing of file parsing mechanisms. Additionally, organizations should consider implementing network-level protections and monitoring for unusual resource consumption patterns that might indicate exploitation attempts, as the vulnerability can be leveraged as part of broader attack campaigns targeting development environments and collaboration platforms.