CVE-2024-49326: Affiliator Plugin RCE Vulnerability

CVE-2024-49326 Overview

CVE-2024-49326 is a critical unrestricted file upload vulnerability affecting the Affiliator (affiliator-lite) WordPress plugin developed by Vasileios Kerasiotis. This vulnerability allows unauthenticated attackers to upload arbitrary files with dangerous types, including web shells, to a vulnerable web server. Successful exploitation enables complete server compromise through remote code execution capabilities.

Critical Impact

Unauthenticated attackers can upload malicious web shells to WordPress installations, leading to complete server takeover, data exfiltration, and persistent backdoor access.

Affected Products

• Affiliator WordPress Plugin versions up to and including 2.1.3
• WordPress installations with the affiliator-lite plugin installed
• All configurations of the affected plugin versions regardless of WordPress settings

Discovery Timeline

• 2024-10-20 - CVE-2024-49326 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2024-49326

Vulnerability Analysis

This vulnerability is classified as CWE-434: Unrestricted Upload of File with Dangerous Type. The Affiliator WordPress plugin fails to properly validate file types during the upload process, allowing attackers to bypass security controls and upload executable scripts such as PHP web shells. Once uploaded, these malicious files can be accessed directly through the web server, enabling remote code execution with the privileges of the web server user.

The vulnerability requires no authentication and can be exploited remotely over the network without any user interaction. An attacker can achieve complete compromise of the confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of CVE-2024-49326 lies in the plugin's insufficient file upload validation mechanism. The Affiliator plugin does not implement proper server-side checks to restrict uploaded file extensions or MIME types. Without adequate validation, the plugin accepts any file type submitted through its upload functionality, including executable PHP files that can serve as web shells.

Proper file upload security requires multiple layers of validation including:

• Server-side extension whitelisting
• MIME type verification
• File content inspection
• Randomized storage paths
• Restricting direct web access to uploaded files

The affected plugin lacks these essential security controls.

Attack Vector

The attack vector for this vulnerability involves network-based exploitation requiring no privileges or user interaction. An attacker can directly interact with the vulnerable file upload endpoint in the Affiliator plugin to submit a malicious PHP web shell. The exploitation flow follows these steps:

1. The attacker identifies a WordPress installation with the vulnerable Affiliator plugin
2. A crafted HTTP request containing a PHP web shell is sent to the plugin's upload endpoint
3. The server accepts the malicious file due to missing file type validation
4. The attacker accesses the uploaded web shell via its URL path
5. Remote command execution is achieved on the server

For technical details regarding this vulnerability, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2024-49326

Indicators of Compromise

• Presence of unexpected PHP files in WordPress upload directories, particularly in wp-content/uploads/ subdirectories
• Unusual file names or randomly generated file names with .php extensions in upload paths
• Web server access logs showing requests to PHP files in upload directories
• Process execution from the web server user account (www-data, apache, nginx) with suspicious commands

Detection Strategies

• Monitor file system changes in WordPress upload directories for new PHP or executable file creation
• Implement web application firewall (WAF) rules to detect and block web shell upload attempts
• Review web server access logs for POST requests to upload endpoints followed by GET requests to newly created PHP files
• Deploy file integrity monitoring solutions to alert on unauthorized file additions

Monitoring Recommendations

• Enable real-time file system monitoring on WordPress wp-content/uploads/ directories
• Configure alerts for any new PHP file creation within upload paths
• Monitor outbound network connections from web server processes for potential command and control traffic
• Implement logging and alerting for unusual process execution patterns from the web server user account

How to Mitigate CVE-2024-49326

Immediate Actions Required

• Immediately disable or remove the Affiliator (affiliator-lite) plugin from all WordPress installations
• Scan WordPress upload directories for unauthorized PHP files or potential web shells
• Review web server access logs for evidence of exploitation attempts
• Consider implementing a WAF with rules to block malicious file uploads

Patch Information

As of the published vulnerability data, versions through 2.1.3 are affected. Website administrators should check for plugin updates and apply the latest patched version when available. Monitor the official WordPress plugin repository and the Patchstack Vulnerability Report for patch announcements.

Workarounds

• Remove or deactivate the Affiliator plugin until a security patch is released
• Implement server-side configuration to block PHP execution in upload directories
• Deploy a web application firewall (WAF) with file upload protection rules
• Restrict access to WordPress admin areas via IP whitelisting or additional authentication

# Apache: Block PHP execution in uploads directory
# Add to .htaccess in wp-content/uploads/
<Files "*.php">
    Require all denied
</Files>

# Nginx: Block PHP execution in uploads directory
# Add to server configuration
location ~* /wp-content/uploads/.*\.php$ {
    deny all;
}