OverTheWire Bandit 19
To gain access to the next level, you should use the setuid binary in the homedirectory. Execute it without arguments to find out how to use it. The password for this level can be found in the usual place (/etc/bandit_pass), after you have used to setuid binary.
In the home folder is the bandit20-do program. Firstly we run with no parameters to get the help message.
Next I run with the whoami command, to see what user context it is running as. Same as file owner.
Finally, we use the program to cat the contents of /etc/bandit_pass/bandit20 password.