Security Optimizer – The All-In-One Protection Plugin < 1.6.5 - Login Access IP Allowlist Bypass via post_password

The Security Optimizer WordPress plugin from 1.5.8 to 1.6.4 does not correctly validate requests to its optional IP-based login restriction feature, allowing the restriction to be bypassed so that unauthenticated requests from non-allowlisted IP addresses can reach and use the login form, defeating the access control the administrator configured.