CVE-2024-9707: Hunk Companion Auth Bypass Vulnerability

CVE-2024-9707 Overview

CVE-2024-9707 is a critical authorization bypass vulnerability in the Hunk Companion plugin for WordPress that allows unauthenticated attackers to install and activate arbitrary plugins through the /wp-json/hc/v1/themehunk-import REST API endpoint. This vulnerability exists due to a missing capability check in all versions up to and including 1.8.4, enabling attackers to leverage the flaw for remote code execution if another vulnerable plugin is installed and activated.

Critical Impact

Unauthenticated attackers can install and activate arbitrary WordPress plugins, potentially leading to complete site compromise and remote code execution.

Affected Products

• Themehunk Hunk Companion versions up to and including 1.8.4
• WordPress installations with Hunk Companion plugin enabled
• Sites using ThemeHunk themes with the companion plugin

Discovery Timeline

• 2024-10-11 - CVE-2024-9707 published to NVD
• 2024-11-25 - Last updated in NVD database

Technical Details for CVE-2024-9707

Vulnerability Analysis

This vulnerability is classified as CWE-862 (Missing Authorization), representing a critical flaw in the Hunk Companion plugin's REST API implementation. The vulnerable endpoint at /wp-json/hc/v1/themehunk-import lacks proper capability checks, allowing any unauthenticated user to interact with the plugin installation and activation functionality. This is particularly dangerous in WordPress environments as it bypasses the standard administrative controls that typically restrict plugin management to authenticated administrators.

The attack requires no user interaction and can be executed remotely over the network with low complexity, making it highly exploitable. Once an attacker successfully installs and activates a malicious or vulnerable plugin, they can achieve complete control over the WordPress site, including arbitrary code execution capabilities.

Root Cause

The root cause of CVE-2024-9707 is a missing authorization check in the app.php file within the Hunk Companion plugin's import functionality. Specifically, the REST API endpoint handler at line 46 of the import/app/app.php file fails to verify that the requesting user has the appropriate WordPress capabilities (such as install_plugins or activate_plugins) before processing plugin installation and activation requests. This oversight allows any remote user, including unauthenticated visitors, to invoke privileged plugin management functions.

Attack Vector

The attack is executed via network-accessible REST API calls to the vulnerable WordPress installation. An attacker can craft HTTP requests to the /wp-json/hc/v1/themehunk-import endpoint to install and activate arbitrary plugins from the WordPress repository or potentially from external sources.

The attack flow involves:

1. Identifying a WordPress site with the vulnerable Hunk Companion plugin installed
2. Sending crafted POST requests to the vulnerable REST API endpoint
3. Installing a known vulnerable or malicious plugin
4. Activating the installed plugin to leverage its vulnerabilities
5. Exploiting the secondary plugin to achieve remote code execution

Technical details regarding the vulnerable code can be found in the GitHub repository source code and the Wordfence vulnerability report.

Detection Methods for CVE-2024-9707

Indicators of Compromise

• Unexpected HTTP POST requests to /wp-json/hc/v1/themehunk-import in web server access logs
• Unauthorized plugin installations appearing in the WordPress plugins directory
• Unknown or suspicious plugins activated without administrator action
• Web server error logs showing REST API activity from unusual IP addresses
• Presence of newly installed plugins with no corresponding administrator activity in WordPress audit logs

Detection Strategies

• Monitor web server access logs for requests to the /wp-json/hc/v1/themehunk-import endpoint, especially from unauthenticated sources
• Implement file integrity monitoring on the wp-content/plugins/ directory to detect unauthorized plugin installations
• Deploy a Web Application Firewall (WAF) with rules to block unauthorized REST API access patterns
• Use WordPress security plugins to audit and alert on plugin installation and activation events

Monitoring Recommendations

• Enable comprehensive logging for all WordPress REST API endpoints
• Configure alerts for any plugin installation or activation events occurring outside of maintenance windows
• Review WordPress user activity logs for anomalous administrative actions
• Implement network monitoring to detect unusual outbound connections that may indicate post-exploitation activity

How to Mitigate CVE-2024-9707

Immediate Actions Required

• Update the Hunk Companion plugin to version 1.8.5 or later immediately
• Audit all installed plugins for any unauthorized or unknown entries
• Review web server access logs for evidence of exploitation attempts
• If compromise is suspected, perform a full site security audit and restore from a known clean backup
• Consider temporarily disabling the plugin if an update cannot be applied immediately

Patch Information

ThemeHunk has released a security patch addressing this vulnerability. The fix implements proper capability checks on the vulnerable REST API endpoint. Users should update to version 1.8.5 or later by accessing the WordPress admin dashboard or through the WordPress plugin repository. The specific code changes can be reviewed in the WordPress Trac Changeset.

Workarounds

• Disable the Hunk Companion plugin entirely until the patch can be applied
• Block access to the /wp-json/hc/v1/themehunk-import endpoint using web server configuration or WAF rules
• Restrict REST API access to authenticated users only at the server level
• Implement IP-based access controls to limit REST API access to trusted networks

# Apache .htaccess configuration to block vulnerable endpoint
<IfModule mod_rewrite.c>
    RewriteEngine On
    RewriteCond %{REQUEST_URI} ^/wp-json/hc/v1/themehunk-import [NC]
    RewriteRule ^(.*)$ - [F,L]
</IfModule>

# Nginx configuration to block vulnerable endpoint
location ~* ^/wp-json/hc/v1/themehunk-import {
    deny all;
    return 403;
}