Author Topic: C code errors  (Read 458 times)

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Kiuhnm

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C code errors
« on: October 17, 2014, 05:16:43 pm »
I'm watching
http://www.youtube.com/watch?feature=player_detailpage&v=lbjS2mXyMEQ#t=2148

Consider the following code:

Code: [Select]
#include <string.h>
#include <stdlib.h>

int main(void) {
  char s1[] = "012345678";
  char dest;
 
  dest = *(char *)malloc(strlen(s1));
}

The author of the video says that the code is vulnerable and an attacker can exploit it.
I don't see how, honestly. I think the author is wrong.
Do you agree?

Offline s3my0n

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Re: C code errors
« Reply #1 on: October 17, 2014, 05:45:33 pm »
Not vulnerable since there is no user input.
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Offline Deque

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Re: C code errors
« Reply #2 on: October 18, 2014, 10:38:03 am »
I don't think you can exploit it in this state. But the code has some serious mistakes, and if it is used productively, it could lead to vulnerable code.
  • malloc(strlen(s1)) --> forgot to allocate space for the string terminator
  • return statement is missing (violates the standard)
  • char dest seems to have the wrong type
« Last Edit: October 18, 2014, 10:38:55 am by Deque »

Offline kenjoe41

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Re: C code errors
« Reply #3 on: October 18, 2014, 05:32:30 pm »
I don't think you can exploit it in this state. But the code has some serious mistakes, and if it is used productively, it could lead to vulnerable code.
  • malloc(strlen(s1)) --> forgot to allocate space for the string terminator
  • return statement is missing (violates the standard)
  • char dest seems to have the wrong type

Ssssh!! Deque is giving C/C++ advice. Cellotape your damn mouth faggot. This only happens once in 40 centuries. The ancestors will flog you for this.
If you can't explain it to a 6 year old, you don't understand it yourself.
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