title: System app : can't execute commands (Permission denied)
body: <p>I have a system app (in the /system/app folder and also signed with the system signature) and I would like to execute some commands.</p>
  
  <p>It works well with adb and superuser rights, but everytime I get a "Permission denied" when I make the call from my application.</p>
  
  <p>This is the kind of command I'm doing :</p>
  
  <pre><code>Runtime.getRuntime().exec("iptables --flush");  
  </code></pre>
  
  <p>Do you know why I have this error ? And how to correct it ?</p>
  
  <p>Thanks !</p>