How to effectively bypass GCC stack smashing detection. But when I overflow the array overflowme the control I never transfered to /bin/sh instead I get something like. stack smashing detected. You don't need to bypass gcc's stack smashing detection. . stack smashing detected. Tricota. Hi, i'm having some trouble with this program. Every time i run it i get the 'stack smashing detected' message and it.
![Detected Detected](/uploads/1/2/5/4/125401129/443534032.png)
Message can only hold 10 bytes. You are copying the string 'Hello World!' Which is 13 bytes (if you count the null character) and you will end up overwriting and corrupting the stack protector cookie.The cookie is a random byte inserted by the compiler to make sure that you crash if the return address is modified on stack, preventing potential buffer overflow exploits.If you are compiling with gcc, to experiment, try adding -fno-stack-protector switch to your compilation statement and trying again. The program will probably crash (but not with a error message like that) and will be vulnerable to buffer overflow exploits. Your message array is 10 characters long (0-9), but if you count 'Hello, World!'
(without the quotes) it is 13 characters long. As such you are overwriting memory that isn't part of your array.For reference, strcpy, strcat and most other C-string functions don't check the length of the array, they assume that you've given it enough space to work with.So, you'll need to give your message array more space.
![Stack Smashing Detected Stack Smashing Detected](/uploads/1/2/5/4/125401129/825096477.jpg)
But how much more? Enough to fit 'Hello, world!' PLUS one more for the null-terminator character '0', which determines the end of the string. So you'll need to declare an array of 14 characters.For a bit more in-depth explanation on working with string and the null-character, i suggest. Whilst it is a C page it covers stuff that is common for both C and C (as C is based on C)Also, as Pearsonartphoto said, you can just declare your array as char message = 'Hello, World!' ;However, if this is for school or a uni assignment, make sure you've been taught to do it this way, because sometimes you can be deducted marks for 'rushing ahead'. The idea of these sort of questions is to teach the funementals, and HOW and WHY certain things work, they may not be the easiest or most efficient way of doing things (the type of stack-smash you're getting is still causing problems in major systems today because programmers forget to check sizes etc).
When I try to run pyhdf.SD.SD(.).datasets, or (.).select(15).get in Python 3.4, I get Stack smashing detected. I can open the same data file fine using the traditional pyhdf in Python 2.7. I'm using Python-hdf4 0.9.See below. $ ipython3 -pylabPython 3.4.1 (default, Jun 18 2014, 10:57:14)Type 'copyright', 'credits' or 'license' for more information.IPython 2.2.0 - An enhanced Interactive Python.? - Introduction and overview of IPython's features.%quickref - Quick reference.help - Python's own help system.object? - Details about 'object', use 'object??'