서버측 요청 위조 공격

서버측 요청 위조 공격

Noncompliant Code Example

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
  URL url = new URL(req.getParameter("url"));
  HttpURLConnection conn = (HttpURLConnection) url.openConnection(); // Noncompliant
}

 

Compliant Solution

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
  String urlWhiteListed = "https://example.com/";
  String str = req.getParameter("url");
  if (!str.startsWith(urlWhiteListed))
    throw new IOException();

  URL url2 = new URL(str);
  HttpURLConnection conn2 = (HttpURLConnection) url2.openConnection(); // compliant
}