Re: Is DEP easily evadable?

[Ben Pfaff <blp () cs stanford edu>]

John Richard Moser <nigelenki () comcast net> writes:

> PaX does pretty nice randomization.  I think 15/16 for heap and stack
> and 24 for mmap(), though I could be overshooting the 24.  I'm on amd64
> so I can't just run paxtest and see; though I could read the source code.

In some fairly reasonable circumstances, this may not be enough.
I wonder whether the security community is generally aware of a
paper I co-authored on defeating PaX and address space
randomization in general on 32-bit systems, titled "On the
Effectiveness of Address Space Randomization".  It was presented
at CCS 2004 and available on my webpage, among other places:
        http://www.stanford.edu/~blp/papers/asrandom.pdf
-- 
"To prepare for the writing of Software,
 the writer must first become one with it,
 sometimes two."
--W. C. Carlson