The vulnerability identified as CVE-2025-11707 affects the Login Lockdown & Protection plugin for WordPress, developed by webfactory. This plugin is designed to protect WordPress sites from brute force login attempts by blocking IP addresses after a number of failed login attempts. However, the plugin uses a key named $unblock_key to allow legitimate users to unblock their IP addresses. The issue lies in the insufficient randomness of this key, classified under CWE-330 (Use of Insufficiently Random Values). Because the $unblock_key is predictable or guessable, an unauthenticated attacker who has access to an administrative user's email address can generate valid unblock keys for their own IP address. This effectively allows the attacker to bypass the IP blocking mechanism that is intended to prevent brute force attacks. The vulnerability affects all versions of the plugin up to and including version 2.14. The CVSS v3.1 base score is 5.3, indicating a medium severity level. The vector string (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N) shows that the attack can be performed remotely over the network without privileges or user interaction, and impacts integrity but not confidentiality or availability. No patches or fixes have been published at the time of disclosure, and no known exploits are reported in the wild. The vulnerability could be exploited to bypass login attempt restrictions, potentially facilitating brute force attacks or unauthorized access attempts by circumventing the plugin’s protective measures.

For European organizations, this vulnerability poses a moderate risk primarily to the integrity of their WordPress-based web applications. By bypassing IP blocks, attackers can repeatedly attempt to guess credentials without being locked out, increasing the likelihood of successful brute force attacks. This can lead to unauthorized access if weak credentials are used, potentially compromising sensitive data or administrative control over websites. The vulnerability does not directly affect confidentiality or availability but weakens a critical security control, indirectly increasing risk. Organizations with publicly accessible admin emails or insufficient email privacy controls are particularly vulnerable. Given the widespread use of WordPress across Europe, especially in small to medium enterprises and public sector websites, exploitation could lead to defacement, data manipulation, or further lateral attacks. The absence of patches means organizations must rely on compensating controls until updates are available. The impact is more pronounced for entities relying heavily on this plugin for login security without additional protective layers such as web application firewalls or multi-factor authentication.

To mitigate this vulnerability, European organizations should first restrict public exposure of administrative email addresses to reduce the attacker's ability to generate valid unblock keys. Employing email obfuscation techniques or limiting email visibility on public-facing pages can help. Until a patch is released, organizations should consider disabling or replacing the Login Lockdown & Protection plugin with alternative security plugins that do not exhibit this weakness. Implementing additional security controls such as multi-factor authentication (MFA) for WordPress logins will significantly reduce the risk of unauthorized access even if brute force attempts succeed. Monitoring login attempts and IP blocking logs can help detect suspicious activity early. Deploying a web application firewall (WAF) with brute force protection capabilities can provide an additional layer of defense. Regularly updating WordPress core and plugins, and subscribing to security advisories from plugin vendors, will ensure timely application of patches once available. Finally, educating administrators about the risks of exposing email addresses and enforcing strong password policies will further reduce exploitation chances.