CVE-2005-3139 in Bugzilla
Summary
by MITRE
Bugzilla 2.19.1 through 2.20rc2 and 2.21, with user matching turned on in substring mode, allows attackers to list all users whose names match an arbitrary substring, even when the usevisibilitygroups parameter is set.
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Analysis
by VulDB Data Team • 06/29/2025
The vulnerability described in CVE-2005-3139 represents a critical information disclosure flaw in Bugzilla version 2.19.1 through 2.20rc2 and 2.21. This issue specifically affects systems where user matching is enabled in substring mode, creating an unintended pathway for attackers to enumerate user accounts within the system. The vulnerability occurs despite the presence of the usevisibilitygroups parameter, which is designed to control user visibility and access permissions. When user matching is configured in substring mode, the system fails to properly enforce access controls, allowing unauthorized enumeration of user accounts based on partial name matches.
The technical implementation of this vulnerability stems from inadequate input validation and access control enforcement within Bugzilla's user matching functionality. The substring matching feature is intended to provide convenient search capabilities for administrators and authorized users, but it lacks proper authorization checks when processing search queries. This flaw enables attackers to submit arbitrary substring queries and receive comprehensive lists of matching user accounts, effectively bypassing the intended security boundaries. The vulnerability is particularly concerning because it operates at the application level, requiring no special privileges or authentication to exploit, making it accessible to any attacker with network access to the Bugzilla instance.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with valuable reconnaissance data that can be used for subsequent attacks. By enumerating user accounts, attackers can identify valid usernames, potentially discover system administrators or developers, and gather intelligence for targeted attacks such as credential stuffing, social engineering, or brute force attempts. The vulnerability directly violates the principle of least privilege and demonstrates a failure in access control mechanisms that should prevent unauthorized users from accessing user account information. This weakness can be categorized under CWE-200 (Information Exposure) and may facilitate techniques aligned with ATT&CK tactic T1087 (Account Discovery) and T1592 (Gather Victim Host Information).
Mitigation strategies for this vulnerability involve multiple layers of security controls. Organizations should immediately upgrade to Bugzilla versions that have patched this vulnerability, as the issue was resolved in subsequent releases. Administrators should also consider disabling user matching functionality when it is not essential for business operations, or implementing additional access controls that restrict user enumeration capabilities. The usevisibilitygroups parameter should be carefully configured and monitored to ensure it properly enforces access restrictions. Network-level controls such as rate limiting and IP-based restrictions on user enumeration endpoints can provide additional protection. Security monitoring should include detection of unusual user enumeration patterns and anomalous search queries that may indicate exploitation attempts. This vulnerability highlights the importance of proper access control implementation and demonstrates how seemingly benign features can create security risks when not properly secured against unauthorized access.