Vulnerability Development mailing list archives

Re: Secure coding in C (was Re: Administrivia #4883)


From: spin () MASSIVE CH (spin0ff)
Date: Fri, 21 Jan 2000 19:32:47 +0100


On Mon, 17 Jan 2000, Valery Dachev wrote:

On Mon, 17 Jan 2000, Vladimir Dubrovin wrote:

Hello Valery Dachev,

17.01.00 12:25, you wrote: Secure coding in C (was Re: Administrivia #4883);

V> Lucky you ! You have encountered the \0 symbol after your buffer and
V> before the end of the segment. Take a look at the situation where the \0
V> symbol is not there. Your program can explode with "Segmentation
V> fault" (or "Segmentation violation" in Windows). There's a simple example
V> in the attachment.
V> Bye.
Your  example  will  fail  regardless  '\0' because there is no bounds
checking for array at all.
This is what I want to demonstrate to Mr.spin0ff ;) This example shows
that when no bound checking, accessing memory address can cause such
errors ;)))

anyway, the question was not whether this will "work" or crash... my
question was "is it exploitable", and if so... how. the segfault problem
was obvious...

  s0


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