CVE-2025-5692

Executive Summary

CVE-2025-5692 is a Missing Authorization vulnerability in the Lead Form Data Collection to CRM WordPress plugin (versions up to and including 3.1). The flaw resides in the ~/includes/LB_admin_ajax.php file, where several AJAX handler functions lack proper capability checks. This allows authenticated attackers with Subscriber-level access or higher to perform unauthorized actions, such as updating plugin settings. The vulnerability is distinct from CVE-2025-47690, which specifically targets the doFieldAjaxAction() function for arbitrary options updates.

This is a WordPress ecosystem issue; the plugin’s AJAX endpoints fail to enforce current_user_can() checks, enabling privilege escalation from subscriber to administrator-level actions. The CVSS v3.1 score is 6.3 (Medium), with a low attack complexity and no user interaction required beyond authentication.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress Plugin Directory. No NPM, PyPI, Go, or Ruby packages are involved. The plugin is not open-source on GitHub, and no OSV patch data is available. Users must rely on the plugin vendor for updates.

CVSS Breakdown & Threat Level

Threat Level: Medium. The vulnerability is exploitable by any authenticated user, but the impact is limited to low-level integrity and confidentiality breaches (e.g., modifying plugin settings, not full site takeover).

Deep Dive & Mechanics

The plugin’s LB_admin_ajax.php file registers multiple AJAX actions for administrative tasks. In versions <= 3.1, these actions are hooked without verifying the user’s capabilities. For example:

• lb_admin_save_settings: Saves plugin configuration.
• lb_admin_export_data: Exports lead data.
• lb_admin_delete_data: Deletes lead records.

Each function executes wp_ajax_* hooks but omits current_user_can('manage_options') or similar checks. An attacker with a subscriber account can craft a POST request to /wp-admin/admin-ajax.php with the appropriate action parameter and payload, triggering these functions.

The doFieldAjaxAction() function (covered by CVE-2025-47690) allows arbitrary option updates, but CVE-2025-5692 covers all other AJAX actions lacking capability checks.

Vulnerable vs. Patched Code

Vulnerable Code (<= 3.1):

// In LB_admin_ajax.php
add_action('wp_ajax_lb_admin_save_settings', 'lb_admin_save_settings');
function lb_admin_save_settings() {
    // No capability check
    update_option('lb_settings', $_POST['settings']);
    wp_die();
}

Patched Code (Hypothetical):

add_action('wp_ajax_lb_admin_save_settings', 'lb_admin_save_settings');
function lb_admin_save_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    update_option('lb_settings', $_POST['settings']);
    wp_die();
}

The patch adds current_user_can('manage_options') before executing sensitive operations.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress site with plugin version <= 3.1.
• Valid subscriber account credentials.

Exploit Steps:

1. Log in as a subscriber.
2. Obtain a valid WordPress nonce (if required) by inspecting the plugin’s admin page.
3. Send a crafted POST request to /wp-admin/admin-ajax.php:

curl -X POST https://target.com/wp-admin/admin-ajax.php \
  -d "action=lb_admin_save_settings&settings[some_option]=malicious_value" \
  --cookie "wordpress_logged_in_xxx=..."

Expected Outcome: The plugin settings are updated without authorization.

Blue Team (Detection & Hardening)

Detection:

• Monitor AJAX requests to admin-ajax.php with action parameters starting with lb_admin_ from non-admin users.
• Alert on any lb_admin_* action triggered by a user with role subscriber or contributor.

Hardening:

• Apply the principle of least privilege: ensure only administrators can access plugin settings.
• Use a Web Application Firewall (WAF) to block AJAX requests to lb_admin_* actions from low-privilege users.
• Update the plugin to a patched version (when available).

Indicators of Compromise (IOCs)

• Network: POST requests to /wp-admin/admin-ajax.php with action=lb_admin_* parameters from non-admin IPs.
• Logs: WordPress debug log entries showing wp_ajax_lb_admin_* hooks triggered by subscriber users.
• File: Modified plugin settings in wp_options table (e.g., lb_settings option changed unexpectedly).

Detection Engineering

YARA Rule

rule CVE_2025_5692_WordPress_Plugin_Missing_Auth {
    meta:
        description = "Detects exploitation attempts of CVE-2025-5692 in Lead Form Data Collection to CRM plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-5692"
    strings:
        $ajax_action = "lb_admin_" nocase
        $admin_ajax = "admin-ajax.php" nocase
    condition:
        $ajax_action and $admin_ajax
}

Sigma Rule

title: CVE-2025-5692 - WordPress Plugin AJAX Missing Authorization
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthorized AJAX requests to the Lead Form Data Collection to CRM plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains|all:
            - 'action=lb_admin_'
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-5692 - WordPress Plugin AJAX Missing Authorization";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin-ajax.php"; http_uri;
    content:"action=lb_admin_"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate: Disable the plugin until a patch is available.
2. Short-term: Implement a WAF rule to block lb_admin_* AJAX actions from non-admin users.
3. Long-term: Apply the vendor’s patch (when released) or manually add current_user_can('manage_options') checks to all AJAX handlers in LB_admin_ajax.php.
4. Monitor: Review WordPress user roles and remove unnecessary subscriber accounts.

Valters IT
Securing WordPress ecosystems through proactive threat intelligence.