CVE-2025-31381: Booking Calendar Auth Bypass Flaw

CVE-2025-31381 Overview

A Missing Authorization vulnerability has been identified in the shiptrack Booking Calendar and Notification WordPress plugin. This vulnerability (CWE-862) allows attackers to exploit incorrectly configured access control security levels, potentially enabling unauthorized actions within the affected WordPress installations.

The vulnerability stems from broken authentication mechanisms in the plugin, which fails to properly validate user authorization before allowing access to protected functionality. This security gap can be exploited remotely without authentication, making it a significant concern for WordPress site administrators using this booking management plugin.

Critical Impact

Unauthenticated attackers can exploit misconfigured access controls in the Booking Calendar and Notification plugin to perform unauthorized actions, potentially compromising booking data integrity and system availability.

Affected Products

• Booking Calendar and Notification plugin versions up to and including 4.0.3
• WordPress installations running vulnerable versions of the plugin
• Sites using shiptrack Booking Calendar and Notification for appointment/booking management

Discovery Timeline

• April 4, 2025 - CVE-2025-31381 published to NVD
• April 7, 2025 - Last updated in NVD database

Technical Details for CVE-2025-31381

Vulnerability Analysis

This Missing Authorization vulnerability (CWE-862) in the Booking Calendar and Notification plugin represents a broken access control flaw that affects all versions from the initial release through 4.0.3. The vulnerability allows exploitation of incorrectly configured access control security levels without requiring authentication.

The attack surface is network-accessible, meaning remote attackers can target vulnerable installations without needing physical access or local presence on the target system. The exploitation complexity is low, as the attack does not require specialized conditions or prerequisites beyond network access to the vulnerable WordPress site.

The impact assessment indicates potential for both data integrity compromise and availability disruption. While confidentiality impact is not indicated, attackers may be able to modify booking data, calendar entries, or notification settings without proper authorization. Additionally, the vulnerability may allow disruption of the booking system's normal operations.

Root Cause

The root cause of this vulnerability lies in the missing authorization checks within the plugin's code paths that handle sensitive operations. The plugin fails to verify whether the user making a request has appropriate permissions before executing protected actions. This allows unauthenticated or low-privileged users to access functionality that should be restricted to administrators or authorized users only.

Attack Vector

The attack vector is network-based, allowing remote exploitation of vulnerable WordPress installations. An attacker can send specially crafted requests to the WordPress site hosting the vulnerable plugin to bypass access control mechanisms. Since no authentication is required and the attack complexity is low, exploitation can be performed by any remote attacker who can reach the target site over the network.

The vulnerability manifests in the plugin's access control implementation where authorization checks are absent or improperly configured. Attackers can leverage this flaw to manipulate booking calendar functionality, alter notification settings, or perform other unauthorized administrative actions within the plugin's scope. For detailed technical information, refer to the Patchstack Vulnerability Advisory.

Detection Methods for CVE-2025-31381

Indicators of Compromise

• Unexpected modifications to booking calendar entries or notification configurations
• Unauthorized AJAX requests to plugin endpoints from unauthenticated sessions
• Anomalous access patterns to booking-related WordPress admin functions
• Log entries showing access to protected plugin functionality without valid authentication tokens

Detection Strategies

• Monitor WordPress access logs for unusual requests targeting the Booking Calendar and Notification plugin endpoints
• Implement web application firewall (WAF) rules to detect and block unauthorized access attempts to plugin-specific URLs
• Deploy file integrity monitoring to detect any unauthorized changes to plugin files or database records
• Configure security plugins to alert on failed authorization attempts and suspicious activity patterns

Monitoring Recommendations

• Enable verbose logging for the Booking Calendar and Notification plugin to capture detailed access information
• Set up real-time alerting for any booking modifications that occur outside normal business workflows
• Monitor for requests to plugin endpoints from IP addresses not associated with legitimate users
• Implement user behavior analytics to identify anomalous access patterns to booking functionality

How to Mitigate CVE-2025-31381

Immediate Actions Required

• Audit current Booking Calendar and Notification plugin version and verify if running version 4.0.3 or earlier
• Review booking data and notification settings for any signs of unauthorized modifications
• Implement additional access controls at the web server or WAF level to restrict access to plugin endpoints
• Consider temporarily disabling the plugin if a patched version is not available and the risk is deemed unacceptable

Patch Information

Site administrators should check for available updates to the Booking Calendar and Notification plugin that address this vulnerability. Monitor the WordPress plugin repository and the Patchstack Vulnerability Advisory for patch availability and update guidance. Ensure automatic updates are enabled for security patches, or manually update to the latest version once a fix is released.

Workarounds

• Implement IP-based access restrictions to limit who can access WordPress admin and plugin functionality
• Deploy a Web Application Firewall (WAF) with rules specifically targeting unauthorized access to booking plugin endpoints
• Require authentication for all plugin-related AJAX endpoints through server-side configuration
• Temporarily restrict access to the booking functionality to authenticated and trusted users only until a patch is applied

# Example .htaccess rules to restrict access to plugin directory
<Directory /var/www/html/wp-content/plugins/booking-calendar-and-notification>
    # Require authentication for all requests
    AuthType Basic
    AuthName "Restricted Access"
    AuthUserFile /etc/apache2/.htpasswd
    Require valid-user
    
    # Alternatively, restrict by IP
    # Require ip 192.168.1.0/24
</Directory>