From owner-freebsd-security Sat Dec 1 9:31:43 2001 Delivered-To: freebsd-security@freebsd.org Received: from oxmail.ox.ac.uk (oxmail3.ox.ac.uk [129.67.1.180]) by hub.freebsd.org (Postfix) with ESMTP id E8E2237B416 for ; Sat, 1 Dec 2001 09:31:40 -0800 (PST) Received: from dhcp212.wadham.ox.ac.uk ([163.1.164.212] helo=piii600.wadham.ox.ac.uk) by oxmail.ox.ac.uk with esmtp (Exim 3.12 #1) id 16ADzH-0002rV-03 for security@FreeBSD.ORG; Sat, 01 Dec 2001 17:31:39 +0000 Reply-To: cperciva@sfu.ca Message-Id: <5.0.2.1.1.20011201171925.035156f8@popserver.sfu.ca> X-Sender: cperciva@popserver.sfu.ca X-Mailer: QUALCOMM Windows Eudora Version 5.0.2 Date: Sat, 01 Dec 2001 17:31:37 +0000 To: security@FreeBSD.ORG From: Colin Percival Subject: Re: philosophical question... In-Reply-To: <3C0903C1.9010108@noos.fr> References: <200112011642.JAA09819@lariat.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org At 17:22 01/12/2001 +0100, Extended Laurent Fabre wrote: >Seems like an OpenBSD feature :P > >But from a security point of view, if an attacker can guess >the random seed, i can't see the protection offered... >It will just raise the number of brute force attacks... I think that a certain amount of protection is given by the fact that an exploit which fails as a result of malloc being nondeterministic would have a good chance of crashing the daemon being attacked. Brute force attacks are hard when each faliure has a chance of making further attempts impossible. ;) Another interesting consideration is that making malloc nondeterministic could make other bugs visible. Still, I have to agree that this sounds pretty OpenBSDish... looking at the BSDs as a whole I'd say it would make sense for this to be added into OpenBSD first and ported to FreeBSD once it has proved itself. Colin Percival To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message