From owner-freebsd-security Sun Jul 19 14:38:26 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA25541 for freebsd-security-outgoing; Sun, 19 Jul 1998 14:38:26 -0700 (PDT) (envelope-from owner-freebsd-security@FreeBSD.ORG) Received: from hotjobs.com (fs3.ny.genx.net [206.64.4.82]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id OAA25534 for ; Sun, 19 Jul 1998 14:38:24 -0700 (PDT) (envelope-from perlsta@fs3.ny.genx.net) Received: (qmail 28997 invoked by uid 1288); 19 Jul 1998 21:37:07 -0000 Received: from localhost (sendmail-bs@127.0.0.1) by localhost with SMTP; 19 Jul 1998 21:37:07 -0000 Date: Sun, 19 Jul 1998 17:37:07 -0400 (EDT) From: Alfred To: Brett Glass cc: security@FreeBSD.ORG Subject: Re: The 99,999-bug question: Why can you execute from the stack? In-Reply-To: <199807192047.OAA02264@lariat.lariat.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org there was a thread about this just a week ago, it was something to do with signals and threads. and breakage of some ancient programs. -Alfred also there was just an announcement about some package to "self-check" executables for stack corruption. On Sun, 19 Jul 1998, Brett Glass wrote: > We're going to be spending about a man-month rebuilding a complex system > that was hacked due to a buffer overflow exploit. Looking back at our > system log files, I can see exactly how the hack was done and how the > perpetrator was able to get root. > > What I CAN'T understand is why FreeBSD allows the hack to occur. Why on > Earth would one want to allow code to be executed from the stack? The Intel > segmentation model normally prevents this, and there's additional hardware > in the MMU that's supposed to be able to preclude it. Why does the OS leave > this gigantic hole open? Why not just close it? > > --Brett Glass > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe security" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe security" in the body of the message