WordPress Front End Editor CVE-2012-10019: Anatomy of an Unauthenticated Arbitrary File Upload Flaw

Introduction

A single unauthenticated HTTP request could hand an attacker the keys to your WordPress site. That was the reality for thousands of websites running vulnerable versions of the Front End Editor plugin before mid-2012. This critical flaw (CVE-2012-10019) enabled attackers to upload and execute arbitrary files—most notably, PHP shells—without any authentication, leading to full site compromise and potential server takeover. The impact was immediate and severe, with public exploits quickly weaponized in automated attack campaigns.

About the Involved Software: Front End Editor was a widely used WordPress plugin developed by scribu, designed to allow users to edit posts and pages directly from the frontend. At its peak, it counted over 10,000 active installations, making it a significant target in the WordPress ecosystem. While not maintained by a large organization, its popularity and integration with the Aloha Editor framework made its security posture critical for a broad segment of the WordPress community.

Technical Information

The vulnerability resided in the upload.php script, located at:

/wp-content/plugins/front-end-editor/lib/aloha-editor/plugins/extra/draganddropfiles/demo/upload.php

This script was intended to facilitate file uploads for frontend editing. However, it failed to implement any form of file type or content validation. The handler accepted HTTP POST requests containing an X-File-Name header, which specified the filename to write on the server. The raw POST body was written directly to disk, regardless of extension or content type.

Vulnerable code pattern:

// Pseudocode representation of the vulnerable logic
$filename = $_SERVER['HTTP_X_FILE_NAME'];
file_put_contents($upload_dir . '/' . $filename, file_get_contents('php://input'));

There were no checks for allowed file extensions, MIME types, or user authentication. This meant that an attacker could upload a file named shell.php containing arbitrary PHP code, which would then be accessible and executable via the web server.

Attack Vector:

The attacker sends a POST request to the vulnerable upload.php endpoint, setting the X-File-Name header to a filename of their choice (e.g., backdoor.php).
The body of the request contains the attacker's payload (e.g., a PHP web shell).
The server responds with a 200 OK, and the file is now present and executable on the server.
The attacker accesses the uploaded file via the browser or command line, achieving remote code execution.

Root Cause: The root cause was a complete absence of input validation and authentication in the file upload handler. The script trusted user-supplied headers and data, writing them directly to the server's filesystem in a web-accessible location.

Exploitation:

No authentication or special privileges were required.
The exploit was trivial to automate and integrate into mass-scanning tools.
Public exploit code and Metasploit modules were released shortly after disclosure, accelerating exploitation in the wild.

For further technical breakdowns and exploit details, see Wordfence, Packet Storm, and NVD.

Patch Information

The vulnerability in the Front-end Editor plugin for WordPress, which allowed arbitrary file uploads, was addressed by implementing stricter file validation and permission checks. The patch introduced a function to verify the MIME type of uploaded files, ensuring only permitted file types are accepted. Additionally, the code was updated to include capability checks, restricting file upload functionality to users with appropriate permissions. These changes effectively prevent unauthorized users from uploading potentially malicious files.

Patch reference: Wordfence Advisory

Affected Systems and Versions

Product: WordPress Front End Editor plugin
Affected Versions: All versions before 2.3
Vulnerable Configuration: Any WordPress site with the plugin installed and enabled, regardless of authentication or user role configuration. The vulnerability does not require any special server configuration; default installs are affected.

Vendor Security History

The Front End Editor plugin was developed by scribu, an independent developer. While the plugin was popular, it lacked a formal security review process. The vendor responded with a patch within days of disclosure, but the plugin has since been closed on the WordPress repository and is no longer maintained. Other plugins by the same author have also exhibited security weaknesses, including insufficient input validation and privilege checks, indicating a broader need for secure development practices in the WordPress plugin ecosystem.

References

Source: This report was created using AI

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