CVE-2025-48155

Executive Summary

CVE-2025-48155 is a Missing Authorization vulnerability in the EnitureTechnology Residential Address Detection WordPress plugin, affecting versions from n/a through 2.5.9. This flaw allows an unauthenticated attacker to access functionality that should be constrained by Access Control Lists (ACLs), leading to unauthorized information disclosure. The vulnerability has a CVSS score of 5.3 (Medium), with a low EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public exploit code or patch is currently available.

WordPress Ecosystem Context

This vulnerability is specific to the WordPress plugin ecosystem. The plugin is designed to detect residential addresses for shipping purposes. The missing authorization check allows unauthenticated users to trigger backend functionality, potentially exposing sensitive configuration data or internal API endpoints. The issue is not related to Apache or Nginx server configurations.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Base Score: 5.3 (Medium)
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – no authentication needed.
• User Interaction: None (UI:N) – no user action required.
• Scope: Unchanged (S:U) – impact confined to the vulnerable component.
• Confidentiality Impact: Low (C:L) – limited information disclosure.
• Integrity Impact: None (I:N) – no data modification.
• Availability Impact: None (A:N) – no denial of service.

Threat Level: Medium. While the CVSS score is moderate, the lack of authentication requirements and the plugin’s widespread use in e-commerce environments elevate the risk. The vulnerability could be chained with other flaws for more severe attacks.

Deep Dive & Mechanics

The vulnerability resides in the plugin’s AJAX handlers or REST API endpoints that are registered without proper capability checks. In WordPress, plugins often expose actions via wp_ajax_ and wp_ajax_nopriv_ hooks. The nopriv hook allows unauthenticated access. If the plugin fails to verify user capabilities (e.g., manage_options, edit_posts) before executing sensitive functions, an attacker can invoke these endpoints directly.

Root Cause: The plugin uses add_action('wp_ajax_nopriv_...', 'callback_function') without a corresponding current_user_can() check inside the callback. This allows any unauthenticated visitor to trigger the function.

Attack Vector: An attacker sends a crafted HTTP POST request to /wp-admin/admin-ajax.php with the appropriate action parameter. The server processes the request and returns data that should be restricted to administrators.

Potential Impact:

• Disclosure of plugin configuration (API keys, service endpoints).
• Exposure of internal WordPress paths or database prefixes.
• Potential for further exploitation if the endpoint allows writing options or triggering other actions.

Vulnerable vs. Patched Code

Since no patch is available, the following illustrates the vulnerable pattern and a hypothetical fix.

Vulnerable Code (PHP):

add_action('wp_ajax_nopriv_residential_detection_check', 'residential_detection_check_callback');

function residential_detection_check_callback() {
    // No capability check
    $address = sanitize_text_field($_POST['address']);
    // Process and return sensitive data
    $result = some_internal_api_call($address);
    wp_send_json_success($result);
}

Patched Code (Hypothetical):

add_action('wp_ajax_residential_detection_check', 'residential_detection_check_callback');
// Remove the nopriv hook to require authentication

function residential_detection_check_callback() {
    // Add capability check
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    $address = sanitize_text_field($_POST['address']);
    $result = some_internal_api_call($address);
    wp_send_json_success($result);
}

Key Differences:

• The nopriv hook is removed, forcing authentication.
• A current_user_can() check is added to restrict access to administrators.
• The function returns a 403 error if the user lacks permissions.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with the plugin installed and active (version <= 2.5.9).
• Network access to the site.

Exploitation Steps:

1. Identify the vulnerable AJAX action. Common actions include residential_detection_check, residential_get_config, or similar.
2. Send a POST request to /wp-admin/admin-ajax.php with the action parameter.
3. Observe the response for sensitive data.

Example cURL Command:

curl -X POST https://target-site.com/wp-admin/admin-ajax.php \
  -d "action=residential_detection_check&address=test"

Expected Output: The server may return JSON containing configuration data, API keys, or internal paths.

Note: No public exploit code is available. The above is a generic exploitation pattern.

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual POST requests to /wp-admin/admin-ajax.php with unknown or suspicious action parameters.
• Look for requests from IPs that are not associated with authenticated users.
• Check for repeated attempts to access AJAX endpoints without a valid session cookie.

Defense:

• Immediately update the plugin if a patch becomes available.
• If no patch, disable the plugin until a fix is released.
• Implement a Web Application Firewall (WAF) rule to block unauthenticated access to plugin-specific AJAX actions.
• Use a WordPress security plugin to monitor for unauthorized AJAX calls.

WAF Rule Example (ModSecurity):

SecRule REQUEST_FILENAME "/wp-admin/admin-ajax.php" \
  "chain,id:1001,deny,msg:'Unauthenticated AJAX access to residential plugin'"
SecRule ARGS:action "^residential_" \
  "chain"
SecRule &REQUEST_COOKIES "!@eq 1" \
  "chain"
SecRule REQUEST_COOKIES:/^wordpress_logged_in_/ "!@rx .+"

Indicators of Compromise (IOCs)

• Network IOCs:

  • POST requests to /wp-admin/admin-ajax.php with action parameter starting with residential_.
  • Source IPs not associated with known admin sessions.
  • Unusual JSON responses containing plugin configuration data.

• File IOCs:

  • Modified plugin files (check file integrity via WordPress checksums).
  • Suspicious log entries in /wp-content/debug.log showing AJAX errors.

• Log IOCs:

  • Apache/Nginx access logs showing repeated POST /wp-admin/admin-ajax.php with action=residential_*.
  • PHP error logs indicating undefined index or unauthorized access attempts.

Detection Engineering

YARA Rule

rule CVE_2025_48155_Residential_Address_Detection {
    meta:
        description = "Detects vulnerable Residential Address Detection plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-48155"
    strings:
        $vuln_hook = "wp_ajax_nopriv_residential_" nocase
        $vuln_func = "function residential_" nocase
    condition:
        $vuln_hook and $vuln_func
}

Sigma Rule

title: CVE-2025-48155 - Unauthenticated AJAX Access to Residential Address Detection
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects unauthenticated POST requests to wp-admin/admin-ajax.php with residential_ action parameters
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: POST
        cs-uri-stem: /wp-admin/admin-ajax.php
        cs-uri-query|contains: action=residential_
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: medium

Suricata Rule

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"CVE-2025-48155 - Unauthenticated AJAX Access to Residential Address Detection";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=residential_"; http_client_body;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
    priority:2;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if it is not critical for business operations.
2. Apply a virtual patch using a WAF to block unauthenticated access to plugin AJAX endpoints.
3. Monitor logs for exploitation attempts.

Long-Term Fix:

• The vendor must release a patched version that adds proper capability checks to all AJAX handlers.
• Until then, consider replacing the plugin with an alternative that has a similar feature set and is actively maintained.

Workaround:

• Add the following code to the theme's functions.php to block unauthenticated access to the plugin's AJAX actions:

add_action('init', function() {
    if (defined('DOING_AJAX') && DOING_AJAX && !is_user_logged_in()) {
        $action = $_REQUEST['action'] ?? '';
        if (strpos($action, 'residential_') === 0) {
            wp_die('Unauthorized', 403);
        }
    }
});

Valters IT
Securing Digital Frontiers