Walkthrough of nebula wargame from level 10 to level 19

In this blog post we will walk through the solutions of the levels 0 to 9 of the Nebula wargame, which is hosted on http://exploit-exercises.com. This writeup will force me to memorize commands better and exercise a bit. I fear that this writeup is of no use for other people, since you hopefully want to solve those exercises on your own :)

Level 0 - Finding setuid programs in the filesystem

As the descriptions states you need to find a setuid binary that gets a shell for the flag00 user. We can find setuid executables with a command such as the following:

find / -type f -perm -4000 -user flag00 2>/dev/null

This command suppresses error messages (The 2>/dev/null part redirects error output to /dev/null). Furthermore the -perm -4000 flag is responsible for

All  of  the  permission bits mode are set for the file.  Symbolic modes are accepted in this form, and this is usually the way in which would want to use
them.  You must specify `u', `g' or `o' if you use a symbolic mode.   See the EXAMPLES section for some illustrative examples.

Now execute the found binary and run getflag and you should be …