CVE-2025-68564: Sendy Authorization Bypass Vulnerability

CVE-2025-68564 Overview

CVE-2025-68564 is a Missing Authorization vulnerability (CWE-862) affecting the Sendy WordPress plugin. This broken access control flaw allows attackers to exploit incorrectly configured access control security levels, potentially enabling unauthorized access to protected functionality or sensitive data within WordPress installations using the vulnerable plugin.

Critical Impact

Unauthenticated attackers can bypass access controls in the Sendy plugin, potentially gaining unauthorized access to administrative functions or sensitive subscriber data managed by the plugin.

Affected Products

• Sendy WordPress Plugin versions up to and including 3.4.2
• WordPress installations with vulnerable Sendy plugin versions

Discovery Timeline

• 2026-02-20 - CVE CVE-2025-68564 published to NVD
• 2026-02-25 - Last updated in NVD database

Technical Details for CVE-2025-68564

Vulnerability Analysis

This vulnerability stems from missing authorization checks within the Sendy WordPress plugin. The plugin fails to properly verify user permissions before allowing access to certain functionality, creating a broken access control condition. An attacker can exploit this flaw remotely over the network without requiring any prior authentication or user interaction.

The vulnerability allows unauthorized users to access functionality that should be restricted to authenticated or privileged users. This can result in exposure of sensitive configuration data or limited modification of plugin settings. The impact includes potential confidentiality breaches through information disclosure and availability concerns through unauthorized modifications.

Root Cause

The root cause is CWE-862: Missing Authorization. The Sendy plugin does not implement proper authorization checks on one or more endpoints or functions. When a request is made to these vulnerable endpoints, the plugin processes the request without verifying whether the requesting user has the necessary permissions to perform the action.

In WordPress plugins, this typically occurs when:

• AJAX handlers lack capability checks using functions like current_user_can()
• REST API endpoints are registered without proper permission callbacks
• Administrative functions are exposed without nonce verification or role validation

Attack Vector

The attack vector is network-based, allowing remote exploitation. An attacker can craft HTTP requests directly to vulnerable plugin endpoints without authentication. The attack requires no user interaction and has low complexity, making it accessible to attackers with minimal technical skills.

A typical attack scenario involves:

1. Identifying a WordPress site using the vulnerable Sendy plugin
2. Crafting requests to endpoints that lack authorization checks
3. Accessing restricted functionality or extracting sensitive information
4. Potentially chaining with other vulnerabilities for greater impact

The vulnerability mechanism involves sending requests to plugin endpoints that should require authentication or specific capabilities but fail to verify these requirements. For detailed technical information, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2025-68564

Indicators of Compromise

• Unexpected HTTP requests to Sendy plugin AJAX endpoints from unauthenticated sources
• Anomalous access patterns to /wp-admin/admin-ajax.php with Sendy-related action parameters
• Unauthorized changes to Sendy plugin configuration or subscriber data
• Web server logs showing requests to plugin endpoints from suspicious IP addresses

Detection Strategies

• Monitor WordPress access logs for unauthenticated requests to Sendy plugin endpoints
• Implement Web Application Firewall (WAF) rules to detect exploitation attempts targeting the Sendy plugin
• Use WordPress security plugins to audit and alert on unauthorized access attempts
• Review plugin activity logs for anomalous operations performed without proper authentication

Monitoring Recommendations

• Enable detailed logging for WordPress AJAX requests and REST API calls
• Set up alerts for high-volume requests targeting the Sendy plugin endpoints
• Regularly audit user activity and plugin configuration changes
• Monitor for reconnaissance activity targeting WordPress plugin enumeration

How to Mitigate CVE-2025-68564

Immediate Actions Required

• Update the Sendy WordPress plugin to a patched version if available from the vendor
• If no patch is available, consider temporarily deactivating the Sendy plugin until a fix is released
• Implement WAF rules to block unauthorized access to vulnerable plugin endpoints
• Review and restrict access to the WordPress admin area using IP allowlisting where feasible

Patch Information

Check the Patchstack Vulnerability Report for the latest patch availability and version information. Ensure all Sendy plugin installations are updated to versions newer than 3.4.2 once a patched release becomes available.

Workarounds

• Restrict access to wp-admin/admin-ajax.php for unauthenticated users at the web server level where possible
• Implement additional authentication layers such as HTTP Basic Auth for administrative endpoints
• Use WordPress security plugins like Wordfence or Sucuri to add virtual patching capabilities
• Monitor and limit access to the plugin's functionality through WordPress capability management

# Apache .htaccess example to restrict AJAX access (use with caution)
<Files admin-ajax.php>
    <RequireAll>
        Require all granted
        # Add IP restrictions as needed
        # Require ip 192.168.1.0/24
    </RequireAll>
</Files>