CVE-2024-0368: Wpmudev Hustle Information Disclosure Flaw

CVE-2024-0368 Overview

CVE-2024-0368 is a sensitive information exposure vulnerability in the Hustle – Email Marketing, Lead Generation, Optins, Popups plugin for WordPress, developed by wpmudev. The flaw affects all versions up to and including 7.8.3 and stems from hardcoded HubSpot API keys embedded in the plugin source code. Unauthenticated attackers can extract these credentials from the publicly accessible plugin code and use them to access sensitive data, including personally identifiable information (PII) collected through marketing forms and opt-ins. The vulnerability is tracked under CWE-522: Insufficiently Protected Credentials.

Critical Impact
Unauthenticated attackers can extract hardcoded API keys from plugin source code and access PII collected through Hustle marketing integrations.

Affected Products

WPMU DEV Hustle plugin for WordPress – all versions up to and including 7.8.3
WordPress sites using the Hustle plugin with HubSpot provider integration
Marketing data and PII collected via Hustle opt-in forms, popups, and lead generation modules

Discovery Timeline

2024-03-13 - CVE-2024-0368 published to the National Vulnerability Database
2026-04-08 - Last updated in NVD database

Technical Details for CVE-2024-0368

Vulnerability Analysis

The Hustle plugin integrates with third-party marketing services, including HubSpot, to manage email campaigns and lead capture. The HubSpot integration module ships with API credentials embedded directly in the PHP source file inc/providers/hubspot/hustle-hubspot-api.php. Because WordPress plugin source code is distributed in clear text and indexed in the public plugin repository, anyone can retrieve the hardcoded values without authenticating to a target site.

An attacker who obtains the keys can interact with the associated HubSpot tenant within the scopes granted to that key. Depending on configured scopes, this includes reading webhook configurations, accessing subscription data, and retrieving contact records that contain PII collected by Hustle-powered forms. The EPSS score of 1.22% (79th percentile) reflects measurable interest in exploitation relative to the broader CVE population.

Root Cause

The root cause is the storage of credentials as static string literals inside a distributed plugin file rather than retrieving them dynamically through a secure server-side broker or per-site OAuth flow. Any user able to download the plugin – which is everyone, since the plugin is hosted on the public WordPress plugin repository – obtains identical credentials. This violates the principle that secrets must never be embedded in client-distributable code.

Attack Vector

Exploitation does not require interaction with any vulnerable WordPress site. An attacker downloads the plugin archive from the WordPress.org repository, opens hustle-hubspot-api.php, and reads the API key directly from the source. The attacker then issues authenticated HTTP requests to HubSpot endpoints using the extracted key. Because the credentials are shared across every installation, a single disclosure impacts the entire user base of the affected provider integration. Review the patched code in the WordPress Popup Changeset Review for the specific lines removed in the fix.

No proof-of-concept code is required beyond reading the affected file and issuing standard HubSpot REST API calls. See the HubSpot API Webhook Management and HubSpot API Webhook Scopes documentation for the API surface reachable with valid credentials.

Detection Methods for CVE-2024-0368

Indicators of Compromise

Outbound HTTP requests from unexpected hosts to api.hubapi.com using the API key embedded in Hustle versions ≤ 7.8.3
Unrecognized webhook subscriptions or contact list exports appearing in the connected HubSpot tenant
Unusual data retrieval volumes against HubSpot endpoints that correlate with the leaked key identifier

Detection Strategies

Inventory all WordPress installations and identify any running the Hustle plugin at version 7.8.3 or earlier
Compare the contents of inc/providers/hubspot/hustle-hubspot-api.php against the patched upstream version to confirm whether hardcoded keys are present
Review HubSpot audit logs for API calls originating from IP addresses outside the organization's expected egress ranges

Monitoring Recommendations

Enable HubSpot account-level alerting for unexpected API token usage and webhook configuration changes
Monitor WordPress site file integrity for the affected PHP file to confirm patch application
Forward web server access logs and outbound proxy logs to a central log analytics platform to correlate API activity with site administration events

How to Mitigate CVE-2024-0368

Immediate Actions Required

Update the Hustle plugin to a version later than 7.8.3 that removes the hardcoded credentials
Rotate any HubSpot API keys and OAuth credentials associated with the affected integration, then audit recent webhook and contact API activity
Audit collected PII for unauthorized access and follow applicable breach notification obligations if exposure is confirmed

Patch Information

The vendor remediated the issue by removing the hardcoded API keys from hustle-hubspot-api.php. The fix is documented in the WordPress Popup Changeset Review and corroborated by the Wordfence Vulnerability Report. Site operators should apply the update through the WordPress plugin manager or via WP-CLI.

Workarounds

Disable the Hustle HubSpot provider integration until the plugin is updated
Restrict the privileges of any HubSpot API key linked to the plugin to the minimum scopes required for marketing operations
Deploy a web application firewall rule set to block anomalous outbound API patterns from WordPress hosts to api.hubapi.com

bash

# Update the Hustle plugin using WP-CLI
wp plugin update wordpress-popup

# Verify installed version is higher than 7.8.3
wp plugin get wordpress-popup --field=version

# If immediate update is not possible, deactivate the plugin
wp plugin deactivate wordpress-popup