The plugin does not properly checks HTTP headers in order to validate the origin IP address, allowing threat actors to bypass it's block feature by spoofing the headers.
The function wantispamp_get_ip() is vulnerable to IP spoofing because of the general usage of $_SERVER['HTTP_X_FORWARDED_FOR']
curl -i -H 'X_FORWARDED_FOR: 0.0.0.0' https://example.com
2022-08-17 (about 1 years ago)
2023-05-10 (about 4 months ago)