--- a/slides/slides03.tex	Mon Oct 06 00:57:44 2014 +0100
+++ b/slides/slides03.tex	Mon Oct 06 02:16:53 2014 +0100
@@ -524,19 +524,65 @@
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \begin{frame}[c]
+\frametitle{The Stack}
+
+\begin{textblock}{7}(1,1)
+  \begin{tikzpicture}[scale=0.8]
+  %\draw[step=1cm] (-3,-1) grid (3,8);
+  \draw[gray!20,fill=gray!20] (-1, 0) rectangle (1,-1);
+  \draw[line width=1mm] (-1,-1.2) -- (-1,7.4);
+  \draw[line width=1mm] ( 1,-1.2) -- ( 1,7.4);
+  \draw (0,-1) node[anchor=south] {\tt main};
+  \draw[line width=1mm] (-1,0) -- (1,0);
+  \draw (0,0) node[anchor=south] {\tt arg$_3$=3};
+  \draw[line width=1mm] (-1,1) -- (1,1);
+  \draw (0,1) node[anchor=south] {\tt arg$_2$=2};
+  \draw[line width=1mm] (-1,2) -- (1,2);
+  \draw (0,2) node[anchor=south] {\tt arg$_1$=1};
+  \draw[line width=1mm] (-1,3) -- (1,3);
+  \draw (0,3.1) node[anchor=south] {\tt ret};
+  \draw[line width=1mm] (-1,4) -- (1,4);
+  \draw (0,4) node[anchor=south] {\small\tt last sp};
+  \draw[line width=1mm] (-1,5) -- (1,5);
+  \draw (0,5) node[anchor=south] {\tt buf$_1$};
+  \draw[line width=1mm] (-1,6) -- (1,6);
+  \draw (0,6) node[anchor=south] {\tt buf$_2$};
+  \draw[line width=1mm] (-1,7) -- (1,7);
+  \draw (2,6.1) node[anchor=south] {\code{$esp}};
+  \draw[<-,line width=0.5mm] (1.1,7) -- (2.5,7);
+
+  \draw[->,line width=0.5mm] (1,4.5) -- (1.8,4.5) -- (1.8, 0) -- (1.1,0); 
+  \draw[->,line width=0.5mm] (1,3.5) -- (2.5,3.5);
+  \draw (2.6,3.1) node[anchor=south west] {\tt back to main()};
+
+  \draw[->,red,line width=2mm] (2.5,0.1) -- (4.2,0.1);
+\end{tikzpicture}
+\end{textblock}
+
+\begin{textblock}{7}(6.4,8)
+\begin{bubble}[6.8cm]
+\footnotesize
+\lstinputlisting[language=C,xleftmargin=5mm]{../progs/example1.c} 
+\end{bubble}
+\end{textblock}
+
+
+\end{frame}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\begin{frame}[c]
 \frametitle{The Problem}
 
 \begin{itemize}
 \item The basic problem is that library routines in C look as follows:
+\end{itemize}
 
 \begin{center}
-\footnotesize\lstinputlisting[language=C]{../progs/app5.c}
+\small\lstinputlisting[language=C,numbers=none]{../progs/app5.c}
 \end{center}
 
-\item the resulting problems are often remotely exploitable 
-\item can be used to circumvents all access control\\
-(for grooming botnets for further attacks)
-\end{itemize}
   
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%