CVE-2005-4171 in eFiction
Summary
by MITRE
The "Upload new image" command in the "Manage Images" eFiction 1.1, when members are allowed to upload images, allows remote attackers to execute arbitrary PHP code by uploading a filename with a .php extension that contains a GIF header, which passes the image validity check but executes any PHP code within the file.
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Analysis
by VulDB Data Team • 06/23/2025
The vulnerability described in CVE-2005-4171 represents a critical security flaw in the eFiction 1.1 content management system that demonstrates a classic file upload vulnerability with remote code execution capabilities. This issue specifically affects the image upload functionality within the "Manage Images" module where authenticated users with member privileges can upload files to the server. The vulnerability stems from inadequate input validation and file type checking mechanisms that fail to properly verify the actual content of uploaded files rather than relying solely on file extensions.
The technical exploitation of this vulnerability occurs through a sophisticated bypass technique that exploits the server's image validation process. Attackers can create malicious files with .php extensions that contain valid GIF headers at the beginning of the file, making the server's image validation routine accept the file as a legitimate image. This approach leverages the fact that many image validation routines check for magic bytes or headers at the beginning of files to determine file type, but fail to verify that the entire file content matches the declared type. The GIF header bytes (47 49 46 38 39 61 or 47 49 46 38 37 61) are sufficient to pass initial validation checks while the remainder of the file can contain arbitrary PHP code that executes when the file is accessed through a web browser.
This vulnerability directly maps to CWE-434, which describes the weakness of unrestricted file upload, and represents a specific implementation of the broader category of insecure file handling practices. The attack vector allows remote code execution with the privileges of the web server process, potentially enabling attackers to gain full control over the affected server, access sensitive data, or use the compromised system as a launching point for further attacks within the network. The vulnerability's impact is particularly severe because it requires no special privileges beyond membership access and can be exploited through a simple web browser interface.
The operational impact of this vulnerability extends beyond immediate code execution capabilities to encompass broader system compromise potential. When an attacker successfully uploads a malicious file, they can execute arbitrary PHP code on the server, potentially leading to data breaches, system infiltration, or the establishment of persistent backdoors. The vulnerability affects not just the immediate web application but can provide attackers with access to the underlying server environment, including other applications and databases hosted on the same system. This type of vulnerability is particularly dangerous in shared hosting environments or when the web server has elevated privileges.
Mitigation strategies for this vulnerability must address both the immediate exploitation vector and the underlying architectural flaws that enable such attacks. The most effective remediation involves implementing strict file type validation that examines the actual content of uploaded files rather than relying solely on extensions or headers. This includes performing comprehensive file analysis using multiple validation techniques such as content inspection, MIME type verification, and file signature checking. Additionally, uploaded files should be stored in non-executable directories, and proper file permissions should be enforced to prevent direct execution of uploaded content. The implementation of a whitelist approach for allowed file types and extensions, combined with regular security audits of file upload mechanisms, provides comprehensive protection against similar vulnerabilities. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for suspicious file upload activities, aligning with ATT&CK technique T1190 for exploitation through web shells and T1059 for command and control through scripting languages.