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Dangerous
chmod u+s /bin/bash

linux · bash · Beginner

Sets the setuid bit on the shell binary, so any user who starts it gets a root shell. This is one of the oldest and most complete privilege escalation backdoors on a Unix system.

Signals to notice

  • u+s makes the binary run as its owner, which is root
  • applying it to a shell hands every local user a root shell

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