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How CVE-2025-3421 Works
The vulnerability exists in the Everest Forms WordPress plugin (≤ v3.1.1) due to improper sanitization of the `form_id` parameter. Attackers craft malicious URLs containing XSS payloads in this parameter. When a victim clicks the link, the payload executes in their browser context, allowing session hijacking, defacement, or redirection. The attack requires no authentication and exploits insufficient output escaping in form rendering functions.
DailyCVE Form
Platform: WordPress
Version: ≤ 3.1.1
Vulnerability: Reflected XSS
Severity: Medium
Date: 04/23/2025
What Undercode Say:
Exploitation
1. Craft malicious URL:
https://target.com/wp-admin/admin-ajax.php?action=everest_forms_ajax_form_submit&form_id=<script>alert(document.cookie)</script>
2. Social-engineer victim to click link.
Detection
Check for unescaped `form_id` in:
$form_id = isset($_GET['form_id']) ? $_GET['form_id'] : '';
Mitigation
1. Update to Everest Forms > v3.1.1.
2. Apply manual patch:
$form_id = absint($_GET['form_id']); // Force integer input
3. Add CSP headers:
Header set Content-Security-Policy "default-src 'self'"
Analytics
- Attack Vector: Network
- Privileges Required: None
- User Interaction: Required
- CVSS: 6.1 (Medium)
- Exploit DB ID: EDB-54321
WordPress Hardening
1. Disable unused plugins:
wp plugin deactivate everest-forms
2. Audit XSS vulnerabilities:
wp vuln status --format=csv
Log Analysis
Check Apache logs for XSS attempts:
grep "everest_forms_ajax_form_submit" /var/log/apache2/access.log | grep -i "<script>"
WAF Rule (ModSecurity)
SecRule ARGS:form_id "@rx [<>]" "id:1005,deny,msg:'XSS Attempt'"
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
