CVE-2023-4629

Executive Summary

CVE-2023-4629 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the LadiApp plugin for WordPress, up to and including version 4.3. The vulnerability exists in the save_config() function, which lacks a nonce check, allowing unauthenticated attackers to forge requests that update the ladipage_config option. Successful exploitation requires tricking a site administrator into performing an action, such as clicking a malicious link. The CVSS score is 4.3 (Medium), with a low EPSS score of 0.0%, indicating low exploitation activity in the wild. No public proof-of-concept or exploit code is available at this time.

WordPress Ecosystem Context

This vulnerability is specific to the LadiApp plugin within the WordPress ecosystem. It does not affect Apache, Nginx, or other server software. The plugin is used for building landing pages, and the CSRF flaw could allow an attacker to modify configuration settings, potentially leading to further compromise.

CVSS Breakdown & Threat Level

• CVSS Score: 4.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (administrator must click a link)
• Scope: Unchanged
• Confidentiality Impact: None
• Integrity Impact: Low
• Availability Impact: None

The threat level is considered low due to the requirement for user interaction and the limited impact on integrity. However, the lack of a patch increases the risk for unmaintained sites.

Deep Dive & Mechanics

The vulnerability resides in the save_config() function of the LadiApp plugin. This function is responsible for saving configuration options, specifically the ladipage_config option. The function does not implement a nonce check, which is a standard WordPress security measure to prevent CSRF attacks. Without a nonce, an attacker can craft a request that appears legitimate to the server, as long as the victim (an administrator) is authenticated.

The attack flow:

1. Attacker crafts a malicious link or form that targets the save_config() endpoint.
2. Attacker tricks an authenticated WordPress administrator into clicking the link or submitting the form.
3. The administrator's browser sends the forged request, including their session cookies.
4. The server processes the request, updating the ladipage_config option with attacker-controlled values.

This could allow the attacker to modify plugin settings, potentially redirecting traffic, injecting malicious scripts, or altering page content.

Vulnerable vs. Patched Code

The vulnerable code in save_config() lacks a nonce verification. A patched version would include a check like check_admin_referer() or wp_verify_nonce().

Vulnerable Code (simplified):

function save_config() {
    // No nonce check
    update_option('ladipage_config', $_POST['config']);
    wp_die();
}

Patched Code (hypothetical):

function save_config() {
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'ladipage_save_config')) {
        wp_die('Security check failed.');
    }
    update_option('ladipage_config', $_POST['config']);
    wp_die();
}

Since no official patch is available, site administrators should consider disabling the plugin or implementing a Web Application Firewall (WAF) rule to block requests to the vulnerable endpoint without a valid nonce.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A WordPress site with LadiApp plugin version <= 4.3.
• An authenticated administrator session.

Exploitation Steps:

1. Identify the vulnerable endpoint: wp-admin/admin-ajax.php?action=ladipage_save_config
2. Craft a CSRF payload (e.g., an HTML form that auto-submits):

<html>
<body>
<form action="http://target.com/wp-admin/admin-ajax.php" method="POST">
    <input type="hidden" name="action" value="ladipage_save_config">
    <input type="hidden" name="config" value='{"malicious":"data"}'>
    <input type="submit" value="Click me">
</form>
<script>document.forms[0].submit();</script>
</body>
</html>

3. Host the payload and send the link to the administrator (e.g., via email or social engineering).
4. Once the administrator clicks, the configuration is updated.

Note: No public exploit code is available; this is a conceptual demonstration.

Blue Team (Defense & Detection)

Detection:

• Monitor for requests to admin-ajax.php with action=ladipage_save_config without a valid nonce parameter.
• Look for unusual changes to the ladipage_config option in the database.

Mitigation:

• Disable the LadiApp plugin until a patch is released.
• Implement a WAF rule to block requests to admin-ajax.php with action=ladipage_save_config unless a valid nonce is present.
• Educate administrators about phishing and social engineering attacks.

Indicators of Compromise (IOCs)

• Network:
  • HTTP POST requests to /wp-admin/admin-ajax.php with parameter action=ladipage_save_config.
  • Referer header from an external domain (indicating CSRF).
• Host:
  • Modified ladipage_config option in the WordPress database (wp_options table).
  • Unexpected changes to LadiApp plugin settings.
• Logs:
  • WordPress debug log entries showing save_config() calls without nonce.

Detection Engineering

YARA Rule

rule CVE_2023_4629_LadiApp_CSRF {
    meta:
        description = "Detects LadiApp plugin CSRF vulnerability exploitation"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2023-4629"
    strings:
        $s1 = "ladipage_save_config" ascii wide nocase
        $s2 = "save_config" ascii wide nocase
        $s3 = "ladipage_config" ascii wide nocase
    condition:
        any of ($s*) and #s1 > 0
}

Sigma Rule

title: CVE-2023-4629 LadiApp CSRF Exploitation
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects CSRF attempts against LadiApp plugin save_config function
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=ladipage_save_config'
    condition: selection
falsepositives:
    - Legitimate plugin updates (if nonce is present)
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2023-4629 LadiApp CSRF Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=ladipage_save_config"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Disable the LadiApp plugin until a patch is released.
2. Workaround: Implement a WAF rule to block requests to admin-ajax.php with action=ladipage_save_config without a valid nonce.
3. Long-term: Monitor the plugin vendor for updates. If no patch is provided, consider replacing the plugin with an alternative.
4. User Education: Train administrators to recognize phishing attempts and avoid clicking suspicious links.
5. Monitoring: Enable logging for WordPress admin-ajax.php requests and review for anomalies.

Valters IT
DevSecOps & Cyber Threat Intelligence