Hands-On System Programming with Linux

An aside – a script to identify setuid-root and setgid installed programs

We now begin to understand that setuid/setgid programs might be convenient, but from a security viewpoint, they can be potentially dangerous and must be carefully audited. The first step in such an audit is finding out whether and where exactly these binaries exist on the Linux system.

To do so, we write a small shell (bash) script; it will identify and show us the installed setuid-root and setgid programs on the system (as usual, you can download and try the script from the book's Git repository).

The script performs its work essentially, as shown next (it actually loops over an array of directories; for simplicity, we show a direct example of scanning the /bin directory): ...