From owner-freebsd-security Fri Dec 18 05:50:30 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id FAA10110 for freebsd-security-outgoing; Fri, 18 Dec 1998 05:50:30 -0800 (PST) (envelope-from owner-freebsd-security@FreeBSD.ORG) Received: from zippy.cdrom.com (zippy.cdrom.com [204.216.27.228]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id FAA10105 for ; Fri, 18 Dec 1998 05:50:29 -0800 (PST) (envelope-from jkh@zippy.cdrom.com) Received: from zippy.cdrom.com (jkh@localhost.cdrom.com [127.0.0.1]) by zippy.cdrom.com (8.9.1/8.9.1) with ESMTP id FAA62541; Fri, 18 Dec 1998 05:50:03 -0800 (PST) To: "Marco Molteni" cc: Guido Stepken , freebsd-security@FreeBSD.ORG Subject: Re: A better explanation (was: buffer overflows and chroot) In-reply-to: Your message of "Fri, 18 Dec 1998 13:56:33 +0100." Date: Fri, 18 Dec 1998 05:50:02 -0800 Message-ID: <62537.913989002@zippy.cdrom.com> From: "Jordan K. Hubbard" Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > In my situation I have a *legitimate* user, call him Bob, who actively > searches such buffer overflows. He does it for research, and he isn't > unserious as you state, I assure you. If he's searching for truely interesting exploits and he needs root priviledge for this, then he must not be very serious about this. :-) It seems a truly dedicated attacker would want to show how things could be exploited *as an ordinary user* in making the case for a serious defense against buffer overflow and other similar types of exploits. Doing it as root is a little like proving you can "break" into a house when you have a full set of keys to all the doors. :-) > So my idea/question is: if I build a chroot jail for Bob, fitted with all > he needs (eg /bin, /usr/bin, /usr/local/bin, /usr/libexec, etc) and I > replace all the suid root binaries with suid root2 binaries, where root2 > is a normal user, he can do his experiments, but he can't get root. No chroot jail is really safe in the hands of someone with root access; he can always use raw device access to get at things outside the jail (or even destroy them inadvertantly during exploit testing). If someone wants to be root on a box, make him get his own to destroy. This is nothing that any computer facilities support department would generally allow, I can say that much, and if I asked for root access as "Bob" in just about any situation I can think of, the owners of the box in question would laugh wildly for about 5 minutes and then tell me to go jump myself. If I want that kind of access, I have to assume that it's going to have to be my own box. - Jordan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message