\documentclass{article}

\usepackage{../style}

\begin{document}

\section*{Homework 3}

\HEADER

\begin{enumerate}

\item How does a buffer-overflow attack work? (Hint: What happens on

  the stack.)

\item Why is it crucial for a buffer overflow attack that the stack

  grows from higher addresses to lower ones?

\item What does it mean for the stack to be executable and why is this

  important for a buffer overflow attack?

\item If the attacker uses a buffer overflow attack in order to inject

  code, why can this code not contain any zero bytes?

\item How does a stack canary help with preventing a buffer-overflow

  attack?

\item Why does randomising the addresses from where programs are run

  help defending against buffer overflow attacks?

\item What is a format string attack?

\item Assume format string attacks allow you to read out the

  stack. What can you do with this information? (Hint: Consider what

  is stored in the stack.)

\item Assume you can crash a program remotely. Why is this a problem?

\item How can the choice of a programming language help with buffer

  overflow attacks?  (Hint: Why are C-programs prone to such attacks,

  but not Java programs.)

\item When filling the buffer that is attacked with a payload

  (starting a shell), what is the purpose of padding the string at the

  beginning with NOP-instructions.

\item In the context of buffer-overflow attacks, explain briefly

what is meant by a \emph{NOP-sledge}.  

\item \POSTSCRIPT

\end{enumerate}

\end{document}

%%% Local Variables: 

%%% mode: latex

%%% TeX-master: t

%%% End: