Executive brief
The Fense Proxy & VPN Blocker plugin for WordPress, which helps websites block unwanted traffic from proxies and VPNs, contains a security flaw that allows unauthorized users to reset its settings. An attacker can remotely clear the plugin's API keys and cached data without needing a password. This could disrupt the plugin's ability to filter traffic and force it to re-authenticate with its service provider, potentially leading to service interruptions or increased operational costs.
Technical details
The vulnerability is classified as Missing Authorization (CWE-862) within the fense_bpvt_save_settings() function. The function is registered to both wp_ajax_* and wp_ajax_nopriv_* hooks, making it accessible to unauthenticated users. Because the function lacks both capability checks and nonce validation, an attacker can trigger the unconditional execution of delete_option() and delete_transient() on specific plugin settings and API key caches. This allows an unauthenticated attacker to reset the plugin's state and force a refetch of API data. The issue is addressed in version 3.0.2.
Affected products
- devozon Fense Proxy & VPN Blocker up to, and including, 3.0.1
Timeline
- 2026-07-17: advisory: NVD publication date
- 2026-07-17: disclosed: Wordfence advisory published
References
- https://plugins.trac.wordpress.org/browser/fense-block-vpn-proxy/tags/2.9.0/includes/system/fense-bpvt-header-code.php
- https://plugins.trac.wordpress.org/browser/fense-block-vpn-proxy/tags/2.9.0/includes/system/fense-bpvt-header-code.php
- https://plugins.trac.wordpress.org/browser/fense-block-vpn-proxy/tags/3.0.2/includes/system/header-code.php?rev=3574545
- https://www.wordfence.com/threat-intel/vulnerabilities/id/1208ac78-4a56-4daa-b935-d579f07f8e8e?source=cve