CVE-2023-6876 – This vulnerability in the Clever Fox WordPress ... (How to Fix)

Q: What is the severity of CVE-2023-6876?

CVE-2023-6876 has a CVSS score of 5.4 (MEDIUM). This vulnerability in the Clever Fox WordPress plugin allows authenticated users with subscriber-level access or higher to change the active theme without proper authorization. Attackers can set invalid theme values that could crash the website. All WordPress sites using vulnerable plugin versions are affected.

📋 TL;DR

This vulnerability in the Clever Fox WordPress plugin allows authenticated users with subscriber-level access or higher to change the active theme without proper authorization. Attackers can set invalid theme values that could crash the website. All WordPress sites using vulnerable plugin versions are affected.

💻 Affected Systems

Products:

Clever Fox – One Click Website Importer by Nayra Themes

Versions: All versions up to and including 25.2.0

Operating Systems: All operating systems running WordPress

Default Config Vulnerable: ⚠️ Yes

Notes: Requires WordPress installation with the vulnerable plugin activated. Any authenticated user (subscriber role or higher) can exploit this.

📦 What is this software?

Clever Fox by Nayrathemes

View all CVEs affecting Clever Fox →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Attackers can set an invalid theme that crashes the WordPress site, causing complete downtime and potential data corruption.

🟠

Likely Case

Attackers change the active theme to disrupt site appearance and functionality, requiring administrative intervention to restore.

🟢

If Mitigated

With proper access controls and monitoring, unauthorized theme changes are detected and reverted before significant impact.

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires authenticated access but is technically simple. The vulnerability is publicly documented with code references.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Versions after 25.2.0

Vendor Advisory: https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&old=3096085%40clever-fox&new=3096085%40clever-fox

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find 'Clever Fox – One Click Website Importer'. 4. Click 'Update Now' if available, or manually update to version after 25.2.0. 5. Verify the plugin is updated to a patched version.

🔧 Temporary Workarounds

Remove vulnerable plugin

all

Temporarily deactivate or remove the Clever Fox plugin until patched version is available

wp plugin deactivate clever-fox
wp plugin delete clever-fox

Restrict user roles

linux

Temporarily restrict subscriber and other low-privilege user accounts from accessing the site

wp user list --role=subscriber --field=ID | xargs wp user meta update <user_id> wp_capabilities 'a:0:{}'

🧯 If You Can't Patch

Disable the Clever Fox plugin immediately
Implement web application firewall rules to block requests to the vulnerable endpoint

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin panel → Plugins → Installed Plugins → Clever Fox version. If version is 25.2.0 or lower, you are vulnerable.

Check Version:

wp plugin get clever-fox --field=version

Verify Fix Applied:

After updating, verify the plugin version is higher than 25.2.0 in WordPress admin panel.

📡 Detection & Monitoring

Log Indicators:

POST requests to /wp-admin/admin-ajax.php with action=clever-fox-activate-theme
Theme switching events from non-administrator users
Failed theme activation attempts

Network Indicators:

HTTP POST requests containing 'clever-fox-activate-theme' parameter

SIEM Query:

source="wordpress.log" AND "clever-fox-activate-theme" AND (user_role="subscriber" OR user_role="contributor" OR user_role="author")

📊 Metadata

CVE ID: CVE-2023-6876

CVSS v3 Score: 5.4 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

CWE: CWE-862

Published: June 7, 2024

Last Updated: November 21, 2024

🔗 References

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🔗 Related Vulnerabilities

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