CVE-2025-69026

Executive Summary

CVE-2025-69026 is an Exposure of Sensitive System Information vulnerability in the Roxnor PopupKit WordPress plugin (specifically the popup-builder-block component). This flaw allows an unauthenticated attacker to retrieve embedded sensitive data from the plugin’s configuration or stored state, leading to information disclosure. The vulnerability affects all versions up to and including 2.1.5. No public exploit code or proof-of-concept is currently available, and the vendor has not released a patch. The CVSS score of 4.3 (Medium) reflects the low complexity and network-based attack vector, but the impact is limited to confidentiality.

Supply Chain & Package Security

This is a WordPress plugin vulnerability. The plugin is distributed via the official WordPress plugin repository and potentially third-party marketplaces. Users should verify the integrity of their plugin files and monitor for any unauthorized modifications. No known supply chain compromise has been reported, but the lack of a patch increases the risk of malicious actors embedding backdoors in unpatched copies.

CVSS Breakdown & Threat Level

Threat Level: Medium. The vulnerability is easy to exploit remotely without authentication, but the information disclosed is limited to embedded sensitive data (e.g., API keys, internal paths, or configuration details). It does not allow code execution or data modification.

Deep Dive & Mechanics

The vulnerability resides in the popup-builder-block component of PopupKit. The plugin fails to properly sanitize or restrict access to internal data stored in JavaScript variables, REST API endpoints, or shortcode attributes. An attacker can craft a request to retrieve sensitive system information such as:

• Database connection strings (if stored in plaintext)
• API keys for third-party services
• Internal file paths or directory listings
• Nonce values or other security tokens

The exposure occurs because the plugin outputs this data directly into the HTML source or exposes it via an unauthenticated REST endpoint without proper authorization checks.

Root Cause: Lack of access control and data sanitization in the popup-builder-block component.

Vulnerable vs. Patched Code

Since no patch is available, the following is a hypothetical comparison based on common remediation patterns.

Vulnerable Code (PHP/JavaScript snippet):

// In popup-builder-block.php
function get_popup_config() {
    $config = get_option('popupkit_config');
    // Directly exposes sensitive data
    wp_send_json($config);
}
add_action('wp_ajax_nopriv_get_popup_config', 'get_popup_config');

Patched Code (Hypothetical):

function get_popup_config() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
    $config = get_option('popupkit_config');
    // Remove sensitive fields before output
    unset($config['api_key']);
    unset($config['db_password']);
    wp_send_json($config);
}
add_action('wp_ajax_get_popup_config', 'get_popup_config');

Exploitation & Lab Setup

Red Team (Exploitation)

1. Reconnaissance: Identify WordPress sites using PopupKit by searching for wp-content/plugins/popupkit/ in the page source or using Shodan dorks.
2. Craft Request: Send a GET request to the vulnerable endpoint (e.g., /wp-admin/admin-ajax.php?action=get_popup_config).
3. Extract Data: Parse the JSON response for sensitive fields.

Example cURL command:

curl -s "http://target.com/wp-admin/admin-ajax.php?action=get_popup_config" | jq '.'

Blue Team (Detection & Hardening)

• Monitor for anomalous AJAX requests to admin-ajax.php with action parameters like get_popup_config from unauthenticated users.
• Implement Web Application Firewall (WAF) rules to block requests to known vulnerable endpoints.
• Disable the plugin until a patch is available, or remove the vulnerable component manually.

Indicators of Compromise (IOCs)

• Network: HTTP requests to /wp-admin/admin-ajax.php with action=get_popup_config or similar.
• File: Presence of popup-builder-block.php in the wp-content/plugins/popupkit/ directory.
• Logs: WordPress debug logs showing wp_ajax_nopriv_get_popup_config calls.
• Response: JSON output containing keys like api_key, db_password, secret, or config.

Detection Engineering

YARA Rule

rule Detect_PopupKit_Sensitive_Data_Exposure {
    meta:
        description = "Detects PopupKit plugin files that may expose sensitive data"
        author = "Valters IT"
        date = "2025-04-10"
        hash = "unknown"
    strings:
        $s1 = "get_popup_config" ascii wide nocase
        $s2 = "wp_ajax_nopriv" ascii wide nocase
        $s3 = "popupkit_config" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: PopupKit Sensitive Data Exposure via AJAX
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated AJAX requests to PopupKit's sensitive data endpoint
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET'
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=get_popup_config'
    condition: selection
falsepositives:
    - Legitimate admin requests (rare)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"PopupKit Sensitive Data Exposure Attempt";
    flow:to_server,established;
    content:"GET"; http_method;
    content:"/wp-admin/admin-ajax.php"; http_uri;
    content:"action=get_popup_config"; http_uri;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate: Disable or uninstall the PopupKit plugin until a patch is released.
2. Short-term: Implement a WAF rule to block requests to admin-ajax.php with action=get_popup_config from unauthenticated users.
3. Long-term: Contact the vendor (Roxnor) for a security update. If no response, consider forking the plugin and applying the hypothetical patch shown above.
4. Monitoring: Enable detailed logging for AJAX requests and review logs for suspicious activity.

Valters IT
DevSecOps & Cyber Threat Intelligence