Need Help with String Format Vulnerabilities and Exploitation

[tunnie]

I'm struggling trying to find out how to do this. Can anyone help?

Complete each of the following tasks for lab_passwd_check and include the following in
your writeup: the input used to complete the task, an explanation of why it worked, and a
screen shot of the terminal when completing the task.
1. Find an input to lab_passwd_check that directly prints the “secret”. Include this in
your writeup.
2. Find an input to lab_passwd_check that overwrites the return value (retVal) with
any value. This will print “Success!” in addition to printing the secret word you
accessed in part 1.
3. Find an input to lab_passwd_check that overwrites the return value (retVal) with
100. This should produce another secret word to include in your writeup.
Extra credit: Find an input to lab_passwd_check that overwrites the return value with the
value of 2. This should produce another secret word to include in your writeup.

[sebas_phoenix]

I'm struggling trying to find out how to do this. Can anyone help?

Complete each of the following tasks for lab_passwd_check and include the following in
your writeup: the input used to complete the task, an explanation of why it worked, and a
screen shot of the terminal when completing the task.
1. Find an input to lab_passwd_check that directly prints the “secret”. Include this in
your writeup.
2. Find an input to lab_passwd_check that overwrites the return value (retVal) with
any value. This will print “Success!” in addition to printing the secret word you
accessed in part 1.
3. Find an input to lab_passwd_check that overwrites the return value (retVal) with
100. This should produce another secret word to include in your writeup.
Extra credit: Find an input to lab_passwd_check that overwrites the return value with the
value of 2. This should produce another secret word to include in your writeup.

Please provide some link as to where you are referring the task from! Also, read this : http://crypto.stanford.edu/cs155old/...string-1.2.pdf