[extropy-chat] Re: SPAM: more news

Christian Weisgerber naddy at mips.inka.de
Wed Feb 18 15:22:57 UTC 2004

Eugen Leitl <eugen at leitl.org> wrote:

> Try 'diversity'. OS X doesn't have a good security school either, but you'll
> see less h4x0rs who can write PowerPC shellcode, simply because Macs are too
> expensive for them. And of course if address space is filled up with
> heterogenous systems (which, incidentally, are more secure by default, simply
> because Windows is such an awful piece of work) you'll get less fulminant
> growth kinetics, once an worm starts cruising the local few-hop 'hood.

Which should be so obvious, I don't understand why it still needs
to be pointed out.  If some blackhat today discovers another buffer
overflow in the MUA I use, and spams the net with an exploit, what
platforms will he target you think?  The FreeBSD/alpha box I happen
to read my mail on will not be on his list.

> Try artificial immune systems, along with natural diversity. It's all the
> rage in the ivory tower, these days. 

Funky catchphrases aside, it would be helpful if more operating
system vendors adopted the safety net technologies pioneered (not
necessarily invented, but first widely deployed) by OpenBSD, such
as ProPolice stack protection; mutual exclusion of writable and
executable memory regions ("W^X"); shared library address randomization;
early dropping of privileges in subsystems that only require special
privileges at startup; and privilege separation in those that require
ongoing special privileges for some operations.

The recent XFree86 font vulnerability was never expoitable on
OpenBSD.  ProPolice catches the buffer overflow, and even without
ProPolice you wouldn't have gained additional privileges since the
X server uses privilege separation and the vulnerability was in the
unprivileged part.

Christian "naddy" Weisgerber                          naddy at mips.inka.de

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