From owner-freebsd-security Tue Oct 1 16:26: 2 2002 Delivered-To: freebsd-security@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2AC6F37B401 for ; Tue, 1 Oct 2002 16:26:01 -0700 (PDT) Received: from pogo.caustic.org (caustic.org [64.163.147.186]) by mx1.FreeBSD.org (Postfix) with ESMTP id E303C43E3B for ; Tue, 1 Oct 2002 16:26:00 -0700 (PDT) (envelope-from jan@caustic.org) Received: from localhost (jan@localhost) by pogo.caustic.org (8.11.6/8.11.6) with ESMTP id g91NPvZ92316; Tue, 1 Oct 2002 16:25:57 -0700 (PDT) (envelope-from jan@caustic.org) Date: Tue, 1 Oct 2002 16:25:57 -0700 (PDT) From: "f.johan.beisser" To: Brett Glass Cc: security@FreeBSD.ORG Subject: Re: tar/security best practice (was Re: RE: Is FreeBSD's tar susceptible to this?) In-Reply-To: <4.3.2.7.2.20021001170815.0345ab20@localhost> Message-ID: <20021001162006.C67581-100000@pogo.caustic.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII 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 On Tue, 1 Oct 2002, Brett Glass wrote: > There are dozens of ways that it can. Think ~/.forward with a piped > command, for example. sadly, i have to admit that won't work, not without adding in the leading "/". remember that "~" is expanded to "/home/$USER". if you can presume your victim will execute from a specific directory - say "/home/foo/tmp" - you could include "./../../.forward" inside a subdirectory. but, what's the guantee that they will be that consistant? assuming they're untarring in /usr/tmp, /var/tmp, or /tmp will also not really work, unless you're attacking a specific victim, and have pre-existing knowledge of their machines setup. while i do see this as being exploitable, i don't see it being something that can't be overcome by education and warning. -------/ f. johan beisser /--------------------------------------+ http://caustic.org/~jan jan@caustic.org "John Ashcroft is really just the reanimated corpse of J. Edgar Hoover." -- Tim Triche To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message