CVE-2005-4518 in Mantis
Summary
by MITRE
Mantis before 0.19.4 allows remote attackers to bypass the file upload size restriction by modifying the max_file_size parameter to (1) bug_file_add.php, (2) bug_report.php, (3) bug_report_advanced_page.php, and (4) proj_doc_add_page.php.
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Analysis
by VulDB Data Team • 07/28/2022
The vulnerability described in CVE-2005-4518 represents a critical access control flaw in the Mantis bug tracking system prior to version 0.19.4. This issue stems from insufficient input validation and parameter manipulation capabilities that allow remote attackers to circumvent built-in security mechanisms designed to restrict file upload sizes. The vulnerability specifically targets four key PHP pages within the application: bug_file_add.php, bug_report.php, bug_report_advanced_page.php, and proj_doc_add_page.php, all of which handle file upload functionality. The flaw enables attackers to modify the max_file_size parameter through direct manipulation of HTTP request parameters, effectively bypassing the intended file size limitations that are typically enforced to prevent resource exhaustion and potential denial of service conditions.
From a technical perspective, this vulnerability constitutes a classic example of parameter tampering and privilege escalation through input manipulation. The flaw occurs because the application fails to properly validate or sanitize user-supplied parameters before processing file upload operations. When an attacker modifies the max_file_size parameter, they can essentially override the server-side restrictions that were designed to limit the maximum file size that can be uploaded to the system. This represents a direct violation of the principle of least privilege and demonstrates inadequate input validation mechanisms. The vulnerability is particularly concerning because it affects multiple file upload endpoints within the application, increasing the attack surface and potential impact.
The operational impact of this vulnerability extends beyond simple bypass of file size restrictions. Attackers can leverage this flaw to upload arbitrarily large files, potentially leading to disk space exhaustion, application instability, and denial of service conditions for legitimate users. The ability to upload large files also opens possibilities for other attack vectors such as exploiting file processing vulnerabilities in the application's handling of uploaded content. Additionally, this vulnerability could enable attackers to consume excessive server resources, potentially causing performance degradation or complete system unavailability. The fact that multiple upload pages are affected suggests that this is not a simple isolated issue but rather a systemic flaw in how the application handles file upload parameters across its interface.
Security practitioners should note that this vulnerability aligns with CWE-20, which describes "Improper Input Validation" as a fundamental weakness that can lead to various security issues including privilege escalation and resource exhaustion. The attack pattern described here also relates to ATT&CK technique T1059, which covers command and scripting interpreters, as attackers may use this capability to upload malicious files that can be executed on the server. Mitigation strategies should focus on implementing proper input validation and parameter sanitization across all file upload endpoints. The most effective approach involves ensuring that server-side file size limits are enforced regardless of client-supplied parameters, implementing proper access controls, and validating all user inputs through robust sanitization processes. Organizations should also consider implementing additional security controls such as file type validation, content inspection, and resource monitoring to prevent abuse of this vulnerability. The recommended solution is to upgrade to Mantis version 0.19.4 or later, where this vulnerability has been addressed through proper parameter validation and enforcement of file size restrictions.