LimitLoginAttempts.php in the limit-login-attempts-reloaded plugin before 2.17.4 for WordPress allows a bypass of (per IP address) rate limits because the X-Forwarded-For header can be forged. When the plugin is configured to accept an arbitrary header for the client source IP address, a malicious user is not limited to perform a brute force attack, because the client IP header accepts any arbitrary string. When randomizing the header input, the login count does not ever reach the maximum allowed retries.

LimitLoginAttempts.php in the limit-login-attempts-reloaded plugin before 2.17.4 for WordPress allows a bypass of (per IP address) rate limits because the X-Forwarded-For header can be forged. When the plugin is configured to accept an arbitrary header for the client source IP address, a malicious user is not limited to perform a brute force attack, because the client IP header accepts any arbitrary string. When randomizing the header input, the login count does not ever reach the maximum allowed retries.