CVE-2002-0809 in Bugzilla
Summary
by MITRE
Bugzilla 2.14 before 2.14.2, and 2.16 before 2.16rc2, does not properly handle URL-encoded field names that are generated by some browsers, which could cause certain fields to appear to be unset, which has the effect of removing group permissions on bugs when buglist.cgi is provided with the encoded field names.
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Analysis
by VulDB Data Team • 09/13/2025
The vulnerability described in CVE-2002-0809 affects Bugzilla versions prior to 2.14.2 and 2.16rc2, representing a critical input validation flaw that exploits how the application processes URL-encoded field names. This issue specifically targets the buglist.cgi component of the bug tracking system, where malformed URL encoding can cause the application to misinterpret field values, leading to unintended operational consequences. The flaw demonstrates a classic example of improper input sanitization and validation that can be exploited to manipulate application behavior through crafted HTTP requests.
The technical root cause of this vulnerability lies in Bugzilla's insufficient handling of URL-encoded parameters within the buglist.cgi script. When browsers generate URL-encoded field names, particularly those containing special characters or sequences that require encoding, the application fails to properly decode and process these values. This misprocessing results in certain fields appearing to be unset within the application's logic, which triggers a cascading effect where group permissions associated with bugs are inadvertently removed. The vulnerability specifically manifests when the application encounters encoded field names that it cannot correctly interpret, causing it to treat them as missing or invalid parameters.
The operational impact of this vulnerability extends beyond simple data handling issues to potentially compromise the security model of the bug tracking system. When group permissions are removed due to improperly handled URL-encoded fields, unauthorized users may gain access to bugs they should not be able to view or modify, effectively undermining the access control mechanisms that protect sensitive information. This permission bypass can lead to information disclosure, unauthorized modifications, and potential escalation of privileges within the Bugzilla environment. The vulnerability is particularly concerning because it can be triggered through normal web browser behavior without requiring special privileges or complex attack vectors.
From a cybersecurity perspective, this vulnerability aligns with CWE-20, which describes improper input validation, and represents a form of parameter manipulation that can be exploited through the application's web interface. The issue also relates to ATT&CK technique T1078 which covers valid accounts and T1566 which involves social engineering through web applications. Organizations using affected Bugzilla versions face significant risk of unauthorized access to classified bug reports, potentially exposing sensitive information about software vulnerabilities, security incidents, or internal development processes. The vulnerability demonstrates how seemingly benign input processing issues can have profound security implications when they affect core access control mechanisms.
The recommended mitigation strategy involves upgrading to Bugzilla versions 2.14.2 or 2.16rc2, which contain the necessary patches to properly handle URL-encoded field names. Administrators should also implement input validation measures at the web application firewall level to detect and block suspicious parameter encoding patterns. Additional protective measures include monitoring for unusual permission changes in bug tracking systems and implementing regular security assessments of web applications. Organizations should also consider implementing proper logging and audit trails for permission-related changes to detect potential exploitation attempts. The vulnerability underscores the importance of robust input sanitization and parameter handling in web applications, particularly those managing sensitive data and access control systems.