// Phase 14 — servlet doPost, vulnerable. // // Reads the POST body from the request stub and feeds it through // `/bin/sh -c`. import java.io.BufferedReader; import java.io.InputStreamReader; public class Vuln { public void doPost(HttpServletRequest req, HttpServletResponse resp) throws Exception { System.out.print("__NYX_SINK_HIT__\n"); String input = req.getBody(); if (input == null) input = ""; String[] cmd = {"/bin/sh", "-c", "echo hello " + input}; Process p = Runtime.getRuntime().exec(cmd); BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream())); String line; while ((line = reader.readLine()) != null) { resp.write(line + "\n"); } p.waitFor(); } }