The WP Private Content Plus through 3.6.2 provides a global content protection feature that requires a password. However, the access control check is based only on the presence of an unprotected client-side cookie. As a result, an unauthenticated attacker can completely bypass the password protection by manually setting the cookie value in their browser.
https://wpscan.com/vulnerability/5295e8da-7aba-4322-981b-80d692b3bc35/