CVE-2023-6220 – The Piotnet Forms WordPress plugin up to versio... (How to Fix)

Q: What is the severity of CVE-2023-6220?

CVE-2023-6220 has a CVSS score of 8.1 (HIGH). The Piotnet Forms WordPress plugin up to version 1.0.26 allows unauthenticated attackers to upload arbitrary files due to insufficient file type validation. This vulnerability can lead to remote code execution on affected WordPress sites. All WordPress installations using vulnerable versions of Piotnet Forms are affected.

📋 TL;DR

The Piotnet Forms WordPress plugin up to version 1.0.26 allows unauthenticated attackers to upload arbitrary files due to insufficient file type validation. This vulnerability can lead to remote code execution on affected WordPress sites. All WordPress installations using vulnerable versions of Piotnet Forms are affected.

💻 Affected Systems

Products:

Piotnet Forms WordPress Plugin

Versions: Up to and including 1.0.26

Operating Systems: Any OS running WordPress

Default Config Vulnerable: ⚠️ Yes

Notes: All installations with vulnerable plugin versions are affected regardless of configuration.

📦 What is this software?

Piotnet Forms by Piotnet

View all CVEs affecting Piotnet Forms →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete server compromise, data theft, malware deployment, or site defacement.

🟠

Likely Case

Attackers upload web shells or malicious scripts to gain persistent access and execute arbitrary commands.

🟢

If Mitigated

File uploads blocked or restricted to safe file types only, preventing code execution.

🌐 Internet-Facing: HIGH - Unauthenticated exploitation makes internet-facing WordPress sites immediately vulnerable.

🏢 Internal Only: MEDIUM - Internal sites are still vulnerable but require network access.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Simple file upload bypass with publicly available proof-of-concept.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 1.0.27 or later

Vendor Advisory: https://plugins.trac.wordpress.org/changeset/3008474/piotnetforms/tags/1.0.27/inc/forms/ajax-form-builder.php

Restart Required: No

Instructions:

1. Log into WordPress admin panel. 2. Go to Plugins → Installed Plugins. 3. Find Piotnet Forms and click 'Update Now'. 4. Verify version is 1.0.27 or higher.

🔧 Temporary Workarounds

Disable Plugin

all

Temporarily disable Piotnet Forms plugin until patched.

wp plugin deactivate piotnetforms

Web Server File Upload Restriction

linux

Configure web server to block uploads to vulnerable endpoint.

# Apache: <LocationMatch "piotnetforms_ajax_form_builder">
    Deny from all
</LocationMatch>
# Nginx: location ~* piotnetforms_ajax_form_builder {
    deny all;
}

🧯 If You Can't Patch

Remove execute permissions from upload directory: chmod -R 644 /wp-content/uploads/
Implement WAF rules to block requests containing 'piotnetforms_ajax_form_builder' and file upload patterns.

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin → Plugins → Piotnet Forms version. If version ≤ 1.0.26, vulnerable.

Check Version:

wp plugin get piotnetforms --field=version

Verify Fix Applied:

Verify Piotnet Forms version is 1.0.27 or higher in WordPress admin.

📡 Detection & Monitoring

Log Indicators:

POST requests to /wp-admin/admin-ajax.php with action=piotnetforms_ajax_form_builder
File uploads to wp-content/uploads/ with suspicious extensions (.php, .phtml, .php7)

Network Indicators:

Unusual outbound connections from WordPress server post-file upload
HTTP requests with multipart/form-data containing executable files

SIEM Query:

source="web_access.log" AND uri="/wp-admin/admin-ajax.php" AND post_data="piotnetforms_ajax_form_builder"

📊 Metadata

CVE ID: CVE-2023-6220

CVSS v3 Score: 8.1 (HIGH)

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

CWE: CWE-434

Published: January 11, 2024

Last Updated: June 3, 2025

🔗 References

https://plugins.trac.wordpress.org/browser/piotnetforms/tags/1.0.26/inc/forms/ajax-form-builder.php#L430 Issue Tracking
https://www.wordfence.com/threat-intel/vulnerabilities/id/af2b7eac-a3f5-408f-b139-643e70b3f27a?source=cve Third Party Advisory
https://plugins.trac.wordpress.org/browser/piotnetforms/tags/1.0.26/inc/forms/ajax-form-builder.php#L430 Issue Tracking
https://www.wordfence.com/threat-intel/vulnerabilities/id/af2b7eac-a3f5-408f-b139-643e70b3f27a?source=cve Third Party Advisory

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2023-6220, you might also want to check these: