CVE-2024-42404

Executive Summary

CVE-2024-42404 is a critical SQL injection vulnerability discovered in the Welcart e-Commerce plugin for WordPress. This flaw allows an authenticated attacker (with login access) to execute arbitrary SQL commands against the underlying database. Successful exploitation can lead to unauthorized access to sensitive data, modification of stored information, and potential privilege escalation within the WordPress ecosystem. The vulnerability affects all versions prior to 2.11.2. No public proof-of-concept (PoC) or exploit code has been released at this time, but the risk remains high due to the widespread use of Welcart in e-commerce environments.

Supply Chain & Package Security

This vulnerability is specific to the Welcart e-Commerce plugin, a third-party component within the WordPress ecosystem. It is not a core WordPress vulnerability. The plugin is distributed via the official WordPress plugin repository and directly from the vendor's website. Users should verify the integrity of the plugin package by checking checksums provided by the vendor. No known supply chain compromise has been reported, but the plugin's update mechanism should be monitored for tampering.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
• Base Score: 7.2 (High)
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: High (PR:H) – The attacker must have valid login credentials to the WordPress admin panel.
• User Interaction: None (UI:N) – No user action is needed.
• Scope: Unchanged (S:U) – The vulnerability does not affect other components.
• Confidentiality Impact: High (C:H) – Full database read access is possible.
• Integrity Impact: High (I:H) – Database records can be modified or deleted.
• Availability Impact: High (A:H) – Database operations can be disrupted.

Threat Level: High. Although authentication is required, the impact is severe. An attacker with low-level admin privileges can escalate to full database control.

Deep Dive & Mechanics

The vulnerability resides in the Welcart e-Commerce plugin's handling of user-supplied input within SQL queries. Specifically, the plugin fails to properly sanitize or parameterize input passed to database queries in certain administrative functions. An authenticated attacker can inject malicious SQL code via input fields such as order IDs, product names, or customer data.

Root Cause: The plugin uses direct string concatenation to build SQL queries without using prepared statements or parameterized queries. For example, a vulnerable code snippet might look like:

$order_id = $_POST['order_id'];
$query = "SELECT * FROM wp_usces_order WHERE id = '$order_id'";
$result = $wpdb->get_results($query);

An attacker can supply a value like 1' OR '1'='1 to bypass authentication or extract data.

Attack Flow:

1. Attacker logs into WordPress with valid credentials (e.g., a subscriber or shop manager account).
2. Attacker navigates to a vulnerable admin page (e.g., order management, product editing).
3. Attacker injects SQL payload into an input field.
4. The payload is executed against the database, allowing data exfiltration, modification, or deletion.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-2.11.2):

// Vulnerable: direct concatenation
$order_id = $_POST['order_id'];
$query = "SELECT * FROM wp_usces_order WHERE id = '$order_id'";
$result = $wpdb->get_results($query);

Patched Code (2.11.2+):

// Patched: using prepared statement
$order_id = $_POST['order_id'];
$query = $wpdb->prepare("SELECT * FROM wp_usces_order WHERE id = %d", $order_id);
$result = $wpdb->get_results($query);

The patch replaces direct string interpolation with $wpdb->prepare(), which escapes and parameterizes the input, preventing SQL injection.

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A WordPress instance with Welcart e-Commerce version < 2.11.2.
• Valid login credentials (e.g., shop manager role).

Exploitation Steps:

1. Log in to WordPress admin.
2. Navigate to the order management page (e.g., /wp-admin/admin.php?page=usces_orderlist).
3. Intercept the request using a proxy (e.g., Burp Suite).
4. Modify the order_id parameter to inject SQL. Example payload:

   order_id=1 UNION SELECT user_login,user_pass FROM wp_users--
   

5. Observe the response for extracted data (e.g., admin credentials).

Automated Exploitation (using sqlmap):

sqlmap -u "http://target/wp-admin/admin-ajax.php?action=usces_order_search" --data="order_id=1" --cookie="wordpress_logged_in_xxx=xxx" --batch --dbs

Blue Team (Defensive)

Detection:

• Monitor for SQL injection patterns in HTTP requests to admin pages.
• Look for unusual characters in parameters like order_id, product_id, or customer_id.
• Alert on multiple failed login attempts followed by SQL-like payloads.

Honeypot:

• Deploy a decoy WordPress instance with Welcart and monitor for injection attempts.

Lab Setup:

• Use Docker to create a vulnerable environment:

  docker run -d --name wp-vuln -p 8080:80 wordpress:latest
  # Install Welcart version 2.11.1 manually
  

• Access at http://localhost:8080.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests containing SQL keywords (UNION, SELECT, OR 1=1) in POST parameters.
  • Requests to /wp-admin/admin-ajax.php with action usces_order_search or similar.
  • Unusual database error messages in HTTP responses (e.g., "You have an error in your SQL syntax").

• Host IOCs:

  • Unexpected entries in the wp_usces_order table.
  • New admin users created via SQL injection.
  • Modified plugin files (e.g., usces_order.php).

• Log IOCs:

  • WordPress debug log entries showing SQL errors.
  • Web server access logs with suspicious query strings.

Detection Engineering

YARA Rule

rule Welcart_SQL_Injection_CVE_2024_42404 {
    meta:
        description = "Detects SQL injection attempts targeting Welcart e-Commerce plugin"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2024-42404"
    strings:
        $s1 = "order_id=" nocase
        $s2 = "UNION" nocase
        $s3 = "SELECT" nocase
        $s4 = "OR 1=1" nocase
        $s5 = "wp_usces_" nocase
    condition:
        any of ($s1, $s5) and any of ($s2, $s3, $s4)
}

Sigma Rule

title: Welcart SQL Injection Attempt
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects SQL injection attempts against Welcart e-Commerce plugin
author: Valters IT
date: 2025-04-10
tags:
    - attack.t1190
    - cve.2024.42404
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 
            - 'order_id='
            - 'product_id='
            - 'customer_id='
        cs-uri-query|contains|all:
            - 'UNION'
            - 'SELECT'
    condition: selection
falsepositives:
    - Legitimate use of UNION in custom queries (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-42404 Welcart SQL Injection Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=usces_order_search"; http_client_body; pcre:"/(order_id|product_id|customer_id)=.*(UNION|SELECT|OR\s+1=1)/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Welcart: Update to version 2.11.2 or later immediately.
2. Restrict Admin Access: Limit login access to trusted users only.
3. Enable Web Application Firewall (WAF): Deploy rules to block SQL injection patterns.

Long-Term Measures:

• Implement input validation and parameterized queries in all custom code.
• Regularly audit WordPress plugins for vulnerabilities.
• Use a security plugin (e.g., Wordfence) to monitor for malicious activity.
• Apply the principle of least privilege to database users.

Workaround (if patching is delayed):

• Disable the vulnerable functionality (e.g., order search) via a custom plugin or .htaccess rewrite.
• Monitor logs for suspicious activity and block offending IPs.

Valters IT