[saagarjha]

Because shells generally provide you with almost unrestricted access to the system, so it’s pretty important that they are secure?

[JacKTrocinskI]

If you already have access to the shell of a system would you not say that you have already defeated many of the security points of the system you are breaking into?

[JacKTrocinskI]

A shell does not grant you unrestricted access to a system, that's absurd, once an attacker gains access to a shell then they still have gain root.