The AA Block Country plugin for WordPress, up to version 1.0.1, suffers from an IP Address Spoofing vulnerability (CVE-2025-13694) due to improper handling of client IP address determination. The plugin relies on user-supplied HTTP headers such as HTTP_X_FORWARDED_FOR to identify the client's IP without verifying whether the server is behind a trusted proxy or validating the authenticity of these headers. This flaw falls under CWE-348, which involves the use of less trusted sources for security decisions. An unauthenticated attacker can craft requests with spoofed X-Forwarded-For headers to bypass IP-based access restrictions implemented by the plugin, effectively circumventing geoblocking or IP filtering controls. The vulnerability does not impact confidentiality or availability directly but compromises the integrity of access control mechanisms. Exploitation requires no privileges or user interaction, making it relatively easy to attempt. No patches or official fixes are currently linked, and no active exploits have been reported in the wild. The vulnerability affects all versions of the plugin up to 1.0.1, which is commonly used in WordPress environments to restrict access based on geographic IP location. The CVSS v3.1 base score is 5.3, reflecting a medium severity with network attack vector, low attack complexity, no privileges required, no user interaction, and impact limited to integrity.

For European organizations, this vulnerability can undermine IP-based access controls used to enforce geofencing, restrict administrative access, or block malicious traffic by country. Attackers can spoof their IP addresses to appear as if they originate from allowed regions or bypass blacklists, potentially gaining unauthorized access to sensitive parts of websites or administrative interfaces. This can lead to unauthorized data manipulation or exposure of internal resources that rely on IP filtering for protection. Although the vulnerability does not directly affect confidentiality or availability, the integrity breach can facilitate further attacks or unauthorized actions. Organizations relying heavily on this plugin for compliance with regional access policies or data residency requirements may face regulatory risks if unauthorized access occurs. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers often target WordPress plugins due to their widespread use.

1. Immediately update the AA Block Country plugin to a patched version once available from the vendor or developer. 2. Until an official patch is released, implement server-side validation to ensure that HTTP_X_FORWARDED_FOR and similar headers are only trusted if originating from known, trusted proxies. 3. Configure web servers and reverse proxies to overwrite or remove untrusted forwarded headers before they reach the WordPress application. 4. Employ additional layers of access control such as multi-factor authentication and application-level authorization checks to reduce reliance on IP-based restrictions. 5. Monitor logs for suspicious patterns of IP spoofing or repeated access attempts with unusual X-Forwarded-For values. 6. Consider disabling the plugin if IP-based blocking is not critical or if alternative geoblocking solutions with better security are available. 7. Educate administrators about the risks of trusting client-supplied headers without validation and encourage regular plugin security audits.