Instead of trying to find "bad" characters, only allow expected characters. For a page parameter, this usually means allowing only alphanumeric characters and rejecting anything containing dots ( ) or slashes ( Canonicalization Check:
: This suggests it is targeting a specific parameter (like page= ) in a URL or form field. -page-....-2F-2F....-2F-2F....-2F-2Fetc-2Fpasswd
: This typically identifies the vulnerable parameter name in a URL (e.g., ://example.com... ). Instead of trying to find "bad" characters, only