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How CVE-2025-3422 Works
The vulnerability exists in Everest Forms plugin (≤ v3.1.1) due to improper validation of user-supplied input before passing it to do_shortcode(). Authenticated attackers with Subscriber-level permissions can inject malicious shortcodes, which are then executed server-side. This occurs because the plugin fails to sanitize or restrict shortcode execution in certain AJAX actions. The attacker crafts a request containing arbitrary shortcodes (e.g.,
</code>), which are processed by WordPress core, leading to potential remote code execution, data leakage, or privilege escalation depending on available shortcodes. <h2 style="color: blue;">DailyCVE Form:</h2> Platform: WordPress Version: ≤ 3.1.1 Vulnerability: Arbitrary Shortcode Execution Severity: Critical Date: 04/24/2025 <h2 style="color: blue;">What Undercode Say:</h2> <h2 style="color: blue;">Exploitation:</h2> <h2 style="color: blue;">1. Payload Example:</h2> [bash] POST /wp-admin/admin-ajax.php HTTP/1.1 action=everest_forms_action&shortcode=[file_php code='evil']
2. Exploit Steps:
- Authenticate as Subscriber.
- Identify vulnerable AJAX hook (
everest_forms_action). - Inject malicious shortcode via `shortcode` parameter.
Protection:
1. Patch: Upgrade to Everest Forms > v3.1.1.
2. WAF Rule:
location ~ admin-ajax.php {
deny /everest_forms_action/;
}
3. WordPress Hardening:
add_filter('do_shortcode_tag', function($output, $tag) {
if (!in_array($tag, ['safe_shortcode1', 'safe_shortcode2'])) {
return '';
}
return $output;
}, 10, 2);
4. Detection Command:
grep -r "do_shortcode" /var/www/html/wp-content/plugins/everest-forms/
5. Mitigation:
- Restrict Subscriber permissions via:
add_filter('user_has_cap', function($caps) { if (current_user_can('subscriber')) { unset($caps['everest_forms_access']); } return $caps; });
6. Log Analysis:
tail -f /var/log/apache2/access.log | grep 'admin-ajax.php.action=everest_forms'
7. Shortcode Sanitization:
function sanitize_shortcode($content) {
return preg_replace('/[(?!allowed_).?]/', '', $content);
}
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
