CVE-2019-25471: FileThingie 2.5.7 RCE Vulnerability

CVE-2019-25471 Overview

CVE-2019-25471 is an arbitrary file upload vulnerability affecting FileThingie 2.5.7, a lightweight web-based file manager. The vulnerability allows unauthenticated attackers to upload malicious files by sending specially crafted ZIP archives through the ft2.php endpoint. Once uploaded, attackers can leverage the application's built-in unzip functionality to extract PHP shells into accessible directories, enabling arbitrary command execution on the target server.

Critical Impact

Unauthenticated remote attackers can achieve full server compromise through arbitrary file upload and subsequent code execution, potentially leading to complete system takeover.

Affected Products

• FileThingie 2.5.7
• Earlier versions of FileThingie 2.x may also be affected

Discovery Timeline

• 2026-03-11 - CVE CVE-2019-25471 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2019-25471

Vulnerability Analysis

This vulnerability is classified as CWE-22 (Path Traversal), though it manifests primarily as an arbitrary file upload issue with path traversal characteristics. The flaw exists in the ft2.php endpoint, which handles file upload operations without proper validation of archive contents or destination paths.

The attack chain involves uploading a ZIP archive containing a malicious PHP file (web shell), then using FileThingie's extraction functionality to unpack the archive into a web-accessible directory. Because the application fails to validate the contents of uploaded archives or restrict the types of files that can be extracted, attackers can place executable PHP code anywhere within the web root.

This vulnerability is particularly severe because it requires no authentication to exploit. An attacker with network access to the FileThingie installation can achieve remote code execution in a two-step process: upload and extract. The resulting web shell provides persistent access and arbitrary command execution capabilities.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and file type restrictions in the file upload and extraction functionality. Specifically, the ft2.php endpoint:

1. Accepts ZIP file uploads without authenticating the user
2. Fails to validate or sanitize the contents of uploaded archives
3. Does not restrict the extraction of executable file types (such as .php files)
4. Allows extraction to web-accessible directories where PHP files can be executed

Attack Vector

The attack leverages network access to the vulnerable ft2.php endpoint. An attacker prepares a ZIP archive containing a PHP web shell, uploads it through the file management interface, and then triggers the extraction functionality. The extracted PHP file becomes accessible via HTTP, allowing the attacker to execute arbitrary commands on the server with the privileges of the web server process.

Detailed exploitation techniques are documented in the Exploit-DB #47349 entry. The attack requires no user interaction and can be fully automated, making it particularly dangerous for internet-facing installations.

Detection Methods for CVE-2019-25471

Indicators of Compromise

• Unexpected PHP files appearing in upload directories or web-accessible paths
• ZIP file uploads to ft2.php from external or unknown IP addresses
• Web server logs showing POST requests to ft2.php followed by GET requests to newly created PHP files
• Unusual process spawning from web server processes (e.g., www-data or apache executing shell commands)

Detection Strategies

• Monitor file system changes in FileThingie upload directories for new .php file creation
• Implement web application firewall (WAF) rules to inspect ZIP archive uploads for embedded executable content
• Review web server access logs for sequential upload and access patterns indicative of web shell deployment
• Deploy file integrity monitoring on web-accessible directories to alert on unauthorized file modifications

Monitoring Recommendations

• Enable verbose logging on the web server and FileThingie application to capture all file operations
• Configure SIEM alerts for patterns matching ZIP upload followed by PHP file access from the same source IP
• Implement network traffic analysis to detect outbound connections originating from web server processes
• Regularly audit upload directories for files with suspicious names or content patterns typical of web shells

How to Mitigate CVE-2019-25471

Immediate Actions Required

• Remove or disable FileThingie 2.5.7 installations from production environments immediately
• Block external access to ft2.php and FileThingie upload directories at the network or web server level
• Audit existing upload directories for any suspicious PHP files or web shells
• Review web server logs for signs of prior exploitation and unauthorized file uploads

Patch Information

FileThingie appears to be an abandoned project with no active maintenance. The GitHub Filethingie Repository has not received updates addressing this vulnerability. Organizations should consider migrating to actively maintained file management solutions.

For additional technical details, refer to the VulnCheck Advisory: Filethingie Upload.

Workarounds

• Implement authentication at the web server level (e.g., HTTP Basic Auth) to restrict access to FileThingie
• Configure web server rules to prevent PHP execution in upload directories using directives like php_flag engine off
• Use .htaccess or equivalent configurations to deny direct access to ft2.php
• Deploy a web application firewall to filter malicious file uploads and block known exploitation patterns

# Apache configuration to disable PHP execution in upload directories
<Directory "/var/www/html/filethingie/uploads">
    php_flag engine off
    Options -ExecCGI
    RemoveHandler .php .phtml .php3 .php4 .php5 .phps
    <FilesMatch "\.ph(p[345]?|tml)$">
        Deny from all
    </FilesMatch>
</Directory>