The YOP Poll WordPress plugin before 7.0.6 does not validate the connection's origin IP address and instead trusts client-controlled forwarding headers when enforcing its per-IP vote restriction, allowing unauthenticated attackers to bypass the vote limit and cast unlimited votes on a public poll.
https://wpscan.com/vulnerability/fc810ca2-3f27-414d-b94a-68842925b7c6/