Common left the back door approach-vulnerability warning-the black bar safety net

For us such a dish hand, finally got the servers is not easy, if it is found it miserable. In fact, the open back door methods there are many, below I to talk, I've learned of several ways. 1. Setuid cp /bin/sh /tmp/. root chmod u-s /tmp/. root Add suid bit to the shell on, although very simple,...