CVE-2006-3676 in planetGallery
Summary
by MITRE
admin/gallery_admin.php in planetGallery before 14.07.2006 allows remote attackers to execute arbitrary PHP code by uploading files with a double extension and directly accessing the file in the images directory, which bypasses a regular expression check for safe file types.
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Analysis
by VulDB Data Team • 08/07/2017
The vulnerability described in CVE-2006-3676 represents a critical file upload security flaw in planetGallery version prior to 14.07.2006. This issue stems from inadequate input validation and file type checking mechanisms within the administrative gallery management component. The vulnerability specifically affects the admin/gallery_admin.php script which handles file uploads for gallery images. Attackers can exploit this weakness by crafting malicious files with double extensions such as .php.jpg or .jpg.php, allowing them to bypass the regular expression validation that is designed to restrict file uploads to safe image formats only.
The technical implementation of this vulnerability demonstrates a classic path traversal and file execution attack vector. When users upload files through the admin interface, the application performs a regular expression check to validate file extensions but fails to properly sanitize or validate the complete filename. This allows attackers to upload PHP files with extensions that appear to be legitimate image formats but actually contain malicious code. Once uploaded, these files can be directly accessed through the images directory, enabling remote code execution on the web server. The vulnerability is particularly dangerous because it bypasses multiple security layers that should prevent execution of PHP scripts from user-uploaded content.
The operational impact of this vulnerability is severe and far-reaching for any system running the affected version of planetGallery. Successful exploitation allows attackers to execute arbitrary PHP code with the privileges of the web server process, potentially leading to complete system compromise. Attackers can upload web shells, backdoors, or other malicious payloads that provide persistent access to the compromised system. This vulnerability directly maps to CWE-434, which describes the weakness of unrestricted file upload, and represents a critical security gap in the application's defense-in-depth strategy. The attack can be executed remotely without requiring authentication, making it particularly dangerous for publicly accessible web applications.
Organizations affected by this vulnerability should immediately implement multiple layers of mitigation. The primary solution involves patching the application to version 14.07.2006 or later, which includes proper file extension validation and sanitization. Additionally, administrators should implement strict file type validation that checks not only the extension but also the file content using MIME type detection. The system should enforce proper file naming conventions and reject any files with multiple extensions or suspicious patterns. Network-level protections such as web application firewalls should be configured to block direct access to uploaded file directories and implement proper file upload restrictions. This vulnerability also aligns with ATT&CK technique T1190 for exploiting vulnerabilities in web applications and T1059 for executing malicious code, highlighting the need for comprehensive security monitoring and incident response procedures.