CVE-2005-3021 in vbulletin
Summary
by MITRE
image.php in vbulletin 3.0.9 and earlier allows remote attackers with access to the administrator panel to upload arbitrary files via the upload action.
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Analysis
by VulDB Data Team • 07/12/2018
The vulnerability described in CVE-2005-3021 represents a critical security flaw in vBulletin 3.0.9 and earlier versions that enables unauthorized file upload capabilities through the image.php script. This issue specifically targets the administrator panel functionality, creating a path for remote attackers to bypass normal security controls and execute malicious code on affected systems. The vulnerability stems from insufficient input validation and access control mechanisms within the file upload process, allowing authenticated administrators with compromised credentials to upload arbitrary files to the server.
This flaw directly maps to CWE-434 which defines "Unrestricted Upload of File with Dangerous Type" as a common weakness in web applications where the system fails to properly validate file types and content during upload processes. The vulnerability exists because the image.php script does not adequately verify the file extensions, MIME types, or content of uploaded files before storing them on the server. Attackers can exploit this by crafting malicious files with extensions that appear legitimate but contain harmful code, potentially leading to remote code execution or server compromise.
The operational impact of CVE-2005-3021 is severe and multifaceted, affecting organizations that rely on vBulletin forums for community engagement and content management. When exploited, this vulnerability allows attackers to upload web shells, malware, or other malicious payloads that can persist on the server long after the initial compromise. The attack vector is particularly dangerous because it requires only administrator-level access, which can be obtained through credential theft, social engineering, or other means of gaining administrative privileges. Once exploited, attackers can use the uploaded files to establish persistent backdoors, exfiltrate sensitive data, or launch further attacks against the internal network.
Organizations should immediately implement multiple layers of mitigation strategies to address this vulnerability. The primary recommendation involves upgrading to vBulletin versions that contain proper file validation and access control mechanisms. Additionally, implementing strict file type restrictions, content scanning, and proper input validation should be enforced at both the application and web server levels. Security measures including network segmentation, monitoring for suspicious file upload activities, and regular security audits should be deployed to detect and prevent exploitation attempts. The vulnerability also highlights the importance of Principle of Least Privilege and regular credential rotation to minimize the impact of potential credential compromise. This issue aligns with ATT&CK technique T1190 which describes "Exploit Public-Facing Application" and demonstrates how vulnerabilities in widely used web applications can provide attackers with persistent access to target environments.
The remediation process requires careful attention to proper patch management and configuration hardening. System administrators should disable unnecessary file upload functionality where possible and implement comprehensive logging of all file upload activities. Regular security assessments should be conducted to identify similar vulnerabilities in other components of the web application stack. Organizations must also establish incident response procedures specifically designed to handle file upload related compromises, including forensic analysis capabilities and automated alerting systems to detect unauthorized file uploads in real-time.