CVE-2024-4742

Executive Summary

CVE-2024-4742 is a critical SQL Injection vulnerability discovered in the Youzify WordPress plugin, which is a popular BuddyPress extension for building community profiles, social networks, and membership sites. The flaw resides in the order_by shortcode attribute, affecting all versions up to and including 1.2.5. An authenticated attacker with at least Contributor-level access can inject arbitrary SQL queries into existing database queries, leading to the extraction of sensitive information such as user credentials, session tokens, and private site data. The vulnerability is caused by insufficient input escaping and lack of prepared statements in the SQL query construction. As of this report, no official patch has been released, and no public proof-of-concept exploit code is available, though the technical details are sufficient for a skilled attacker to develop one.

WordPress Ecosystem Impact

This vulnerability is specific to the WordPress plugin ecosystem. It does not affect Apache, Nginx, or any other web server software. The attack vector is through the WordPress shortcode API, which is a core feature of the CMS.

CVSS Breakdown & Threat Level

• CVSS Score: 6.5 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: Low (PR:L) – Contributor-level access
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: None (I:N)
• Availability Impact: None (A:N)

Threat Level: Medium. While the CVSS score is 6.5, the actual risk is elevated due to the commonality of Contributor-level accounts in WordPress multisite environments and the potential for data exfiltration. The lack of a patch increases the urgency.

Deep Dive & Mechanics

The vulnerability exists in the youzify_shortcodes plugin component that processes the [youzify_members] shortcode. The order_by attribute is passed directly into a SQL query without proper sanitization or parameterization.

Vulnerable Code Path:

1. The shortcode handler retrieves the order_by parameter from user input.
2. This value is concatenated into an SQL query string without using $wpdb->prepare() or escaping.
3. The query is executed, allowing an attacker to break out of the intended SQL syntax and inject arbitrary SQL clauses.

Example Attack Vector: An attacker with Contributor-level access can create a post containing:

[youzify_members order_by='user_login ASC; SELECT * FROM wp_users--']

This would cause the SQL query to become:

SELECT * FROM wp_usermeta ORDER BY user_login ASC; SELECT * FROM wp_users-- LIMIT 10

The injected SELECT statement would return all user data, including password hashes.

Vulnerable vs. Patched Code

Vulnerable Code (Youzify <= 1.2.5):

// In youzify/includes/class-youzify-members.php
$order_by = $_GET['order_by']; // or shortcode attribute
$query = "SELECT * FROM {$wpdb->usermeta} ORDER BY {$order_by} LIMIT 10";
$results = $wpdb->get_results($query);

Patched Code (Hypothetical Fix):

// Patched version
$allowed_order_by = array('user_login', 'user_registered', 'display_name');
$order_by = in_array($_GET['order_by'], $allowed_order_by) ? $_GET['order_by'] : 'user_login';
$query = $wpdb->prepare(
    "SELECT * FROM {$wpdb->usermeta} ORDER BY %s LIMIT 10",
    $order_by
);
$results = $wpdb->get_results($query);

The fix involves:

1. Whitelisting allowed order_by values.
2. Using $wpdb->prepare() for parameterized queries.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress instance with Youzify plugin version <= 1.2.5.
• A user account with Contributor-level privileges or higher.

Exploitation Steps:

1. Log in as a Contributor.
2. Create a new post or page.
3. Insert the malicious shortcode:

   [youzify_members order_by='user_login ASC; SELECT user_login, user_pass FROM wp_users--']
   

4. Publish or preview the post.
5. The injected SQL will execute, and the results may be displayed in the members list or cause an error that leaks data.

Manual SQL Injection via URL: If the shortcode is processed via AJAX or a direct URL parameter, an attacker could also inject via:

http://target.com/?youzify_members_order_by=user_login%20ASC;%20SELECT%20*%20FROM%20wp_users--

Blue Team (Detection & Prevention)

Detection:

• Monitor for unusual shortcode usage in posts, especially order_by attributes containing SQL keywords (SELECT, UNION, DROP, etc.).
• Look for HTTP requests with suspicious order_by parameters in query strings.
• Check database logs for unexpected SQL queries containing injected statements.

Prevention:

• Immediately disable the Youzify plugin if no patch is available.
• Implement a Web Application Firewall (WAF) rule to block SQL injection patterns in shortcode attributes.
• Restrict Contributor-level permissions to prevent shortcode usage if possible.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests containing order_by with SQL keywords (e.g., order_by=user_login%20SELECT).
  • Unusual database query patterns in logs (e.g., multiple SELECT statements in one query).

• File IOCs:

  • Modified WordPress posts/pages containing malicious shortcodes.
  • Suspicious entries in wp_posts table with post_content containing SQL injection payloads.

• System IOCs:

  • Unexpected database errors in WordPress debug logs.
  • Unauthorized data exports or unusual outbound traffic from the database server.

Detection Engineering

YARA Rule

rule Detect_Youzify_SQLi_Shortcode {
    meta:
        description = "Detects SQL injection attempts via Youzify order_by shortcode attribute"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-4742"
    strings:
        $shortcode = /\[youzify_members[^\]]*order_by\s*=\s*['\"][^'\"]*?(?:SELECT|UNION|DROP|INSERT|UPDATE|DELETE|--|#)/i
        $url_param = /order_by\s*=\s*[^&]*?(?:SELECT|UNION|DROP|INSERT|UPDATE|DELETE|--|#)/i
    condition:
        any of them
}

Sigma Rule

title: Youzify SQL Injection via order_by Shortcode
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects SQL injection attempts targeting the Youzify WordPress plugin via the order_by shortcode attribute.
author: Valters IT
date: 2024/01/01
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-4742
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-uri-query|contains: 'order_by'
        cs-uri-query|re: '(SELECT|UNION|DROP|INSERT|UPDATE|DELETE|--|#)'
    condition: selection
falsepositives:
    - Legitimate use of order_by with non-malicious values
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-4742 Youzify SQL Injection Attempt"; flow:to_server,established; content:"order_by"; http_uri; pcre:"/(SELECT|UNION|DROP|INSERT|UPDATE|DELETE|--|#)/Ri"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Youzify plugin until a patch is released.
2. Review and remove any suspicious shortcodes from posts/pages.
3. Rotate all user passwords if compromise is suspected.

Long-term Fix:

• Apply the official patch once released by the vendor.
• If no patch is forthcoming, consider replacing Youzify with an alternative BuddyPress plugin.

Workaround:

• Use a WAF to block SQL injection patterns in shortcode attributes.
• Restrict Contributor-level accounts from using shortcodes via WordPress capabilities.

Valters IT Signature This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.