In this chapter we learned what a chroot jail is, and how it can help increase security by isolating a server process by placing it inside a "jail" confined to a specific directory. We saw an example of the kind of attack that could be used to gain access to a system once a remote hole has been found, and how a jail would have stopped the attack since the binaries required to complete the attack would not be available inside the jail.
We looked at the traditional way of putting a process in jail by using the chroot binary or the chroot() system call, and saw how ModSecurity helps simplify the process by working from within Apache to achieve the chroot functionality after Apache has initialized. Finally, we learned some caveats to watch out for when using SecChrootDir.
In the next chapter we will be looking at REMO, which is a graphical editor to create ModSecurity rules.
