CVE-2007-3199 in Link Request Contact Form
Summary
by MITRE
Unrestricted file upload vulnerability in Link Request Contact Form 3.4 allows remote attackers to execute arbitrary PHP code by uploading a file with a .php extension and an image content type, as demonstrated by image/jpeg.
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Analysis
by VulDB Data Team • 09/21/2024
The vulnerability identified as CVE-2007-3199 represents a critical unrestricted file upload flaw within the Link Request Contact Form plugin version 3.4. This security weakness stems from inadequate input validation and sanitization mechanisms that fail to properly verify file types and content before allowing uploads to proceed. The vulnerability specifically affects web applications that utilize this plugin for handling contact form submissions and link requests, creating a significant attack surface for malicious actors seeking to compromise affected systems.
The technical implementation of this flaw occurs when the application accepts file uploads without proper validation of the file extension or MIME content type. Attackers can exploit this by crafting a malicious PHP file with a .php extension but with an image content type such as image/jpeg. The plugin's insufficient validation logic allows these files to bypass security checks, enabling attackers to upload executable code that can be executed within the web server context. This type of vulnerability falls under the CWE-434 category, which specifically addresses unrestricted upload of file with dangerous type, and represents a classic path traversal and code execution vulnerability.
The operational impact of this vulnerability extends beyond simple code execution capabilities, as it provides attackers with persistent access to the affected web server environment. Once successfully exploited, the malicious PHP file can be executed to perform various malicious activities including data exfiltration, system reconnaissance, privilege escalation, and establishing backdoors for continued access. The vulnerability demonstrates a fundamental failure in the principle of least privilege and proper input validation, allowing attackers to upload files that could compromise entire web applications and underlying infrastructure. This type of attack aligns with ATT&CK technique T1190 which covers exploitation of remote services and T1059 which involves execution through command and scripting interpreter.
Mitigation strategies for this vulnerability require immediate implementation of proper file validation mechanisms including strict extension filtering, content type verification, and the use of secure file upload libraries. Organizations should implement multiple layers of defense including web application firewalls, proper file type checking, and the use of non-executable upload directories. The recommended approach involves rejecting files with potentially dangerous extensions regardless of their reported content type, implementing proper MIME type validation, and ensuring that uploaded files are stored outside the web root directory. Additionally, regular security audits and vulnerability assessments should be conducted to identify similar issues in other components of the web application stack. The vulnerability also highlights the importance of keeping all third-party plugins and applications updated, as this flaw was present in version 3.4 and likely existed in earlier versions as well.