ethical hacking
Ethical Hacking Lab 5
Buffer Overflow and Steganography
Determine the conditions for a buffer overflow to occur and use Steganography to demonstrate the manner to hide messages within a picture or other media.
Given the program below:
#include <stdio.h>
#include <string.h>
void foo(int a, int b, int c)
{
int tmp;
a=2;
tmp = b+c*a;
}
int main(int argc, char * argv[])
{
int pass = 0;
char buff[15];
foo(3,4,5);
printf("\n Enter the password : \n");
gets(buff);
if(strcmp(buff, "testpilot"))
{
printf ("\n Wrong Password \n");
}
else
{
printf ("\n Correct Password \n");
pass = 1;
}
if(pass)
{
/* Now Give root or admin rights to user*/
printf ("\n Root privileges given to the user \n");
}
return 0;
}
Assume the program is in a file called: test.c
It is compiled and linked using gcc test.c –a test
and is executed as ./test
Show the activation records up to where the arrow indicates:
Parameter right-to-left local variables top-to-bottom word size is 32 bits
Show what input, other than testpilot will give root privileges.
___________________________________________________________________________
What are DEP and ASLR?
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
How do these techniques prevent attacks on the system?
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
Given the following original and stego images
Determine
The maximum percentage of changed bits _____________________
The actual number of changed bits ___________________________
Using the original image, but now using single bit (lsb) and only hiding the letter c,
The maximum percentage of changed bits _____________________
The actual number of changed bits ___________________________