CVE-2025-67578

Executive Summary

CVE-2025-67578 is a Missing Authorization vulnerability in the WordPress plugin WP Email Capture by Rhys Wynne, affecting versions through 3.12.4. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized actions within the plugin's functionality. The vulnerability is classified as a CWE-862: Missing Authorization, with a CVSS score of 5.3 (Medium). No public proof-of-concept (PoC) or exploit code has been identified at this time, and the patch status remains unknown.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. Users who have installed WP Email Capture from the WordPress dashboard or via direct download are affected. The plugin is not distributed via NPM, PyPI, Go, or Ruby ecosystems. Administrators should monitor the plugin's page for updates and apply patches as soon as they become available.

CVSS Breakdown & Threat Level

• CVSS Score: 5.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: None
• Integrity Impact: Low
• Availability Impact: None

The low EPSS score (0.0%) suggests that exploitation is not currently widespread, but the lack of authentication requirements makes this a potential target for automated scanning.

Deep Dive & Mechanics

The vulnerability stems from missing authorization checks in the WP Email Capture plugin. The plugin likely exposes certain REST API endpoints or AJAX actions that should require administrative privileges but do not. An unauthenticated attacker can send crafted HTTP requests to these endpoints to perform actions such as modifying plugin settings, exporting captured email data, or triggering email captures without proper validation.

The affected component is the plugin's core functionality for capturing and managing email addresses. The missing authorization allows an attacker to bypass access controls, potentially leading to data leakage or configuration tampering.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the plugin's main PHP files. A typical vulnerable pattern might look like:

// Vulnerable code (wp-email-capture.php)
add_action('wp_ajax_nopriv_capture_email', 'handle_capture_email');
function handle_capture_email() {
    // No capability check
    update_option('wp_email_capture_settings', $_POST);
}

A patched version would include a capability check:

// Patched code
add_action('wp_ajax_nopriv_capture_email', 'handle_capture_email');
function handle_capture_email() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
    update_option('wp_email_capture_settings', $_POST);
}

Exploitation & Lab Setup

Red Team

To exploit this vulnerability in a lab environment:

1. Setup: Install WordPress with WP Email Capture plugin version 3.12.4.
2. Reconnaissance: Identify exposed endpoints using tools like wpscan or manual inspection of plugin source code.
3. Exploitation: Send a crafted HTTP request to the vulnerable endpoint without authentication.

Example using curl:

curl -X POST http://target/wp-admin/admin-ajax.php \
  -d 'action=capture_email&email=attacker@example.com'

If the endpoint allows configuration changes, an attacker could modify plugin settings:

curl -X POST http://target/wp-admin/admin-ajax.php \
  -d 'action=update_settings&option=wp_email_capture_settings&value=malicious'

Blue Team

To detect exploitation attempts:

1. Monitor Logs: Check web server access logs for unusual POST requests to admin-ajax.php with action=capture_email or similar parameters.
2. Network Analysis: Look for anomalous traffic patterns from unauthenticated sources targeting plugin-specific endpoints.
3. File Integrity: Monitor changes to WordPress options table for unauthorized modifications to wp_email_capture_settings.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-ajax.php with action=capture_email or action=update_settings from unauthenticated IPs.
• File: Unexpected changes to the wp_email_capture_settings option in the WordPress database.
• Log: Entries in WordPress debug log showing unauthorized access attempts to plugin functions.

Detection Engineering

YARA Rule

rule Detect_WP_Email_Capture_Exploit {
    meta:
        description = "Detects exploitation attempts against CVE-2025-67578"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-67578"
    strings:
        $s1 = "action=capture_email" nocase
        $s2 = "action=update_settings" nocase
        $s3 = "wp_email_capture" nocase
    condition:
        any of ($s*) and filesize < 10KB
}

Sigma Rule

title: WP Email Capture Missing Authorization Exploit
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects unauthenticated POST requests to WP Email Capture endpoints
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=capture_email'
    condition: selection
falsepositives:
    - Legitimate plugin usage from authenticated users
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-67578 WP Email Capture Missing Authorization Exploit";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=capture_email"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate Action: Disable the WP Email Capture plugin until a patch is released.
2. Workaround: Implement a web application firewall (WAF) rule to block unauthenticated requests to admin-ajax.php with suspicious parameters.
3. Monitoring: Enable detailed logging for WordPress and review logs for unauthorized access attempts.
4. Update: Monitor the plugin's official page for updates and apply patches as soon as they become available.
5. Alternative: Consider using a different email capture plugin with proper authorization controls.

Valters IT
Securing Digital Frontiers