CVE-2023-50838 – This SQL injection vulnerability in the NEX-For... (How to Fix)

📋 TL;DR

This SQL injection vulnerability in the NEX-Forms WordPress plugin allows attackers to execute arbitrary SQL commands through the form builder. It affects all WordPress sites using NEX-Forms versions up to 8.5.5. Successful exploitation could lead to database manipulation, data theft, or complete system compromise.

💻 Affected Systems

Products:

NEX-Forms – Ultimate Form Builder WordPress plugin

Versions: All versions up to and including 8.5.5

Operating Systems: Any OS running WordPress

Default Config Vulnerable: ⚠️ Yes

Notes: Affects all WordPress installations with vulnerable plugin versions installed and activated.

📦 What is this software?

Nex Forms by Basixonline

View all CVEs affecting Nex Forms →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete database compromise leading to data theft, privilege escalation, and potential remote code execution through database functions.

🟠

Likely Case

Data exfiltration from WordPress database including user credentials, sensitive form submissions, and site configuration.

🟢

If Mitigated

Limited impact with proper input validation and database permissions, potentially only allowing data viewing without modification.

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

SQL injection vulnerabilities in WordPress plugins are frequently weaponized quickly after disclosure.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 8.5.6 or later

Vendor Advisory: https://patchstack.com/database/vulnerability/nex-forms-express-wp-form-builder/wordpress-nex-forms-ultimate-form-builder-8-5-5-sql-injection-vulnerability

Restart Required: No

Instructions:

1. Log into WordPress admin panel
2. Navigate to Plugins → Installed Plugins
3. Find NEX-Forms plugin
4. Click 'Update Now' if available
5. If no update available, download version 8.5.6+ from WordPress repository
6. Deactivate old version and upload new version
7. Activate updated plugin

🔧 Temporary Workarounds

Disable vulnerable plugin

all

Temporarily disable NEX-Forms plugin until patched

wp plugin deactivate nex-forms-express-wp-form-builder

Web Application Firewall rules

all

Implement WAF rules to block SQL injection patterns targeting NEX-Forms endpoints

🧯 If You Can't Patch

Implement strict input validation and parameterized queries for all form submissions
Restrict database user permissions to minimum required for plugin functionality

🔍 How to Verify

Check if Vulnerable:

Check WordPress admin → Plugins → Installed Plugins for NEX-Forms version 8.5.5 or earlier

Check Version:

wp plugin get nex-forms-express-wp-form-builder --field=version

Verify Fix Applied:

Verify plugin version is 8.5.6 or higher in WordPress admin panel

📡 Detection & Monitoring

Log Indicators:

Unusual SQL queries in WordPress or database logs
Multiple failed login attempts after form submissions
Unexpected database schema changes

Network Indicators:

POST requests to /wp-admin/admin-ajax.php with SQL patterns in parameters
Unusual outbound database connections from web server

SIEM Query:

source="wordpress.log" AND "nex-forms" AND ("SELECT" OR "UNION" OR "INSERT" OR "UPDATE" OR "DELETE")

📊 Metadata

CVE ID: CVE-2023-50838

CVSS v3 Score: 7.6 (HIGH)

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

CWE: CWE-89

Published: December 28, 2023

Last Updated: November 21, 2024

🔗 References

📤 Share & Export

📄 Export Markdown 📋 Export JSON

🔗 Related Vulnerabilities

If you're affected by CVE-2023-50838, you might also want to check these: