Source code for CSCI 476 @ MSU - Computer Security

Includes some code examples from class.

Mostly adopted from "Computer & Internet Security: A Hands-on Approach" (2nd Edition) by Wenliang (Kevin) Du.

https://www.handsonsecurity.net

Tips & Tricks

Configure gdb to ensure it uses att syntax

# make sure default assembly syntax is att syntax. ONLY NEED TO RUN THIS ONCE!
echo 'set disassembly-flavor att' >> ~/.gdbinit

Disable ASLR

sudo sysctl -w kernel.randomize_va_space=0;

Updating the Shell

On the SEED VM, /bin/sh is actually an alias for /bin/dash.

# sh is actually an alias
$ which sh
/bin/sh
$ ls -l /bin/sh
lrwxrwxrwx 1 root root 8 Jan 23 03:32 /bin/sh -> /bin/dash

/bin/dash has countermeasures against some of our exercises. So, at times we may need to use another shell, such as /bin/zsh. Here are examples of how to set/reset the shell symlinks:

$ sudo ln -sf /bin/zsh /bin/sh   # make sh symlink to zsh
$ sudo ln -sf /bin/dash /bin/sh  # sh is symlink to dash (default)