CVE-2018-17455 in Community Edition
Summary
by MITRE • 04/16/2023
An issue was discovered in GitLab Enterprise Edition before 11.1.7, 11.2.x before 11.2.4, and 11.3.x before 11.3.1. Attackers could obtain sensitive information about group names, avatars, LDAP settings, and descriptions via an insecure direct object reference to the "merge request approvals" feature.
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Analysis
by VulDB Data Team • 05/05/2023
The vulnerability identified as CVE-2018-17455 represents a critical insecure direct object reference flaw within GitLab Enterprise Edition that affected multiple version streams prior to specific patch releases. This security weakness allowed unauthorized attackers to access sensitive information about group configurations and settings through improperly controlled access to merge request approvals functionality. The issue stems from inadequate input validation and access control mechanisms that failed to properly authenticate and authorize requests targeting group-specific resources within the GitLab platform.
The technical implementation of this vulnerability manifests through the improper handling of object references within the merge request approvals feature. When attackers accessed certain endpoints related to group information, they could retrieve group names, avatar images, LDAP configuration details, and descriptive metadata without proper authorization. This occurs because the application fails to validate whether the requesting user has legitimate access rights to the target group resources, creating an avenue for information disclosure attacks. The flaw operates at the application logic level, where direct object references are used without proper access control checks, making it a classic example of insecure direct object reference as classified by CWE-284.
The operational impact of this vulnerability extends beyond simple information disclosure, as the exposed data could provide attackers with significant reconnaissance information for subsequent attacks. Group names and descriptions might reveal organizational structure and project relationships, while LDAP settings could expose authentication configurations that attackers could leverage for privilege escalation or lateral movement within the environment. Avatar images, though seemingly benign, could contain metadata or be used in social engineering attacks. This vulnerability aligns with ATT&CK technique T1213.002 for data from information repositories, enabling adversaries to gather intelligence for more sophisticated attacks.
Organizations utilizing affected GitLab versions face substantial risk of unauthorized access to sensitive organizational information, potentially compromising the security posture of their entire code repository infrastructure. The vulnerability particularly affects enterprises that rely heavily on GitLab's group-based access controls and collaborative features, where the exposure of group metadata could reveal project dependencies, team structures, and authentication mechanisms. Mitigation strategies should include immediate patching to the recommended versions, implementation of proper access control validation for all object references, and comprehensive security reviews of similar features within the application. Additionally, organizations should consider network segmentation, monitoring for anomalous access patterns, and regular security assessments to identify and remediate similar vulnerabilities in their GitLab deployments.