CVE-2023-3443 in GitLab
Summary
by MITRE • 12/01/2023
An issue has been discovered in GitLab affecting all versions starting from 12.1 before 16.4.3, all versions starting from 16.5 before 16.5.3, all versions starting from 16.6 before 16.6.1. It was possible for a Guest user to add an emoji on confidential work items.
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Analysis
by VulDB Data Team • 10/03/2024
The vulnerability identified as CVE-2023-3443 represents a privilege escalation issue within GitLab's access control mechanisms that affects multiple version ranges including 12.1 through 16.4.2, 16.5 through 16.5.2, and 16.6 through 16.6.0. This flaw specifically targets the confidentiality controls surrounding work items within GitLab's issue tracking and project management features. The vulnerability stems from insufficient authorization checks that allow users with minimal privileges to perform actions typically restricted to higher-privileged roles. Guest users who should only have read-only access to project content can exploit this weakness to add emojis to confidential work items, effectively bypassing the intended security boundaries that protect sensitive project information from unauthorized modification.
The technical implementation of this vulnerability lies in GitLab's insufficient validation of user permissions when processing emoji addition requests on work items. When a Guest user attempts to add an emoji to a confidential work item, the system fails to properly verify whether the user possesses sufficient privileges to modify the item's metadata or annotations. This authorization bypass occurs at the application logic level where the system should enforce mandatory access controls based on user roles and item confidentiality levels. The flaw manifests as a failure in the access control decision-making process, allowing unauthorized modifications to occur despite the presence of security controls designed to protect confidential data.
The operational impact of this vulnerability extends beyond simple data modification as it creates a potential vector for information disclosure and manipulation within GitLab environments. Guest users can inadvertently or maliciously add emojis to confidential work items, potentially altering the metadata or appearance of sensitive issues without proper authorization. This behavior undermines the integrity of confidential project information and could enable attackers to gather intelligence about project status, priorities, or sensitive details through subtle modifications that might not be immediately apparent. The vulnerability particularly affects organizations that rely on GitLab's confidentiality features to protect sensitive project data, development timelines, or strategic information from unauthorized access or modification by less privileged users.
Security professionals should consider this vulnerability in the context of CWE-285, which addresses improper authorization within software systems, and aligns with ATT&CK technique T1078.004 for valid accounts and privilege escalation. Organizations should implement immediate mitigations including applying the relevant GitLab patches, reviewing user access controls, and monitoring for unauthorized emoji additions to confidential work items. The fix typically involves strengthening authorization checks to ensure that only users with appropriate permissions can modify work item metadata, including emoji additions. Additionally, administrators should conduct comprehensive access reviews to identify any other potential privilege escalation vectors within the GitLab instance and consider implementing additional monitoring controls to detect anomalous behavior patterns that might indicate exploitation attempts.
This vulnerability highlights the importance of proper access control implementation in collaborative development platforms where users with varying privilege levels interact with sensitive project information. The flaw demonstrates how seemingly minor functionality can create significant security risks when authorization controls are not properly enforced across all system operations. Organizations should treat this vulnerability as a reminder of the critical need for thorough security testing of access control mechanisms, particularly in environments where multiple user roles interact with confidential data. The impact extends to compliance requirements where unauthorized modifications to confidential work items could violate data protection regulations or organizational security policies governing access to sensitive information.