Question $2$: $[10$ points$]$

You have been asked to perform a security audit of one of your company's applications. You

discover the following:

There is a format string vulnerability that an attacker could exploit.

The program's stack and heap are marked as non$-$executable $($NX$),$ which means that the

attacker cannot place their shellcode into any of the program's variables or arrays.

However, you discovered a second vulnerability: the application uses dynamic linking to load in

an external library at runtime. The library is loaded into memory at a fixed address of $0x4000,$

and the memory it occupies is marked as both writable and executable.

Briefly explain how an attacker could potentially exploit this.