HTTPCookie erroneously save cookie

According to rfc-6265, The user agent will reject cookies unless the Domain attribute specifies a scope for the cookie that would include the origin server.

but in iOS, I can save cookies even the Domain attribute is different to server.

Below is my code

      for cookie in HTTPCookieStorage.shared.cookies ?? [] {
        HTTPCookieStorage.shared.deleteCookie(cookie)
      }

      let urlString = "http://aa.bbb.net/bb/cc"
      let cookie = HTTPCookie.cookies(withResponseHeaderFields: ["Set-Cookie": "key1=value1;Domain=baidu.com"], for: URL(string: urlString)!)
      HTTPCookieStorage.shared.setCookie(cookie.first!)

      for cookie in HTTPCookieStorage.shared.cookies ?? [] {
        print(cookie)
      }

      let getCookie = HTTPCookieStorage.shared.cookies(for: URL(string: "http://www.baidu.com/bb/cc")!)
      print(getCookie)

In the above code, I can successfully get my cookie “key1=value1”，this should be wrong？What confuses me is how do I fix this？