CVE-2008-2717 in TYPO3
Summary
by MITRE
TYPO3 4.0.x before 4.0.9, 4.1.x before 4.1.7, and 4.2.x before 4.2.1, uses an insufficiently restrictive default fileDenyPattern for Apache, which allows remote attackers bypass security restrictions and upload configuration files such as .htaccess, or conduct file upload attacks using multiple extensions.
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Analysis
by VulDB Data Team • 08/01/2021
The vulnerability identified as CVE-2008-2717 affects TYPO3 content management systems across multiple version ranges including 4.0.x before 4.0.9, 4.1.x before 4.1.7, and 4.2.x before 4.2.1. This security flaw resides in the Apache web server configuration defaults that TYPO3 employs for file upload restrictions. The issue stems from an insufficiently restrictive fileDenyPattern parameter that fails to adequately prevent malicious file uploads through the web application's file handling mechanisms.
The technical implementation of this vulnerability occurs when TYPO3 applications running on Apache servers utilize default security configurations that do not properly restrict file extensions during upload operations. The fileDenyPattern parameter serves as a crucial security control that should prevent the upload of potentially dangerous file types including configuration files such as .htaccess, which could allow attackers to modify server behavior or execute malicious code. The insufficient restriction allows attackers to bypass these security controls by using multiple file extensions or by exploiting the default configuration to upload files that would normally be blocked.
From an operational perspective, this vulnerability presents significant risks to TYPO3 installations as it enables remote attackers to conduct file upload attacks without requiring authentication or privileged access. Attackers can leverage this weakness to upload malicious configuration files that could modify server behavior, execute arbitrary code, or establish persistent access points within the web application environment. The ability to upload .htaccess files specifically poses additional risks as these files can modify Apache server directives and potentially allow attackers to bypass security restrictions, redirect traffic, or enable dangerous server configurations that could compromise the entire hosting environment.
The impact of this vulnerability extends beyond simple file upload capabilities and represents a critical security weakness that aligns with CWE-434, which describes insecure file upload vulnerabilities where applications accept files from untrusted sources without proper validation. This weakness allows for potential privilege escalation, remote code execution, and persistent backdoor establishment within the affected web application infrastructure. The vulnerability also correlates with ATT&CK technique T1195.001 which involves uploading files to gain initial access to systems, making it a foundational entry point for more sophisticated attack vectors.
Organizations should immediately implement mitigations by updating their TYPO3 installations to versions 4.0.9, 4.1.7, or 4.2.1, which contain the corrected fileDenyPattern configurations. Additionally, administrators should review and strengthen their Apache server configurations to ensure that file upload restrictions are properly enforced through custom fileDenyPattern settings that explicitly block dangerous file extensions including .htaccess, .php, .pl, .cgi, and other potentially malicious file types. Network segmentation and web application firewalls should also be implemented to monitor and restrict file upload traffic, while regular security audits should verify that no unauthorized files have been uploaded to the system. The remediation process must include thorough testing of updated configurations to ensure that legitimate file uploads continue to function properly while malicious uploads are effectively prevented.