Security vulnerability issue (PHP)

I have the psoudoe code of the following script:

        $ pass = & # 39 ;;
$ answer = & # 39; .... & # 39;

extract ($ _GET);

if (($ inp)) {
if ($ inp === get_contents ($ pass)) {
returns $ answer
} other {
echo "False!"
}
}

My task is to find the variable $ answer. I have an HTML form that passes the input parameter of the field in this script with the help of the GET method. What type of attack could this script be vulnerable to? I am a beginner in this field, so any help would be greatly appreciated.

P. I have read on the PHP website that the extraction () with $ _GET is a very bad idea. Could this be because it makes XSS attacks possible against this script?