From owner-freebsd-questions Wed Jul 24 10:01:38 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id KAA00736 for questions-outgoing; Wed, 24 Jul 1996 10:01:38 -0700 (PDT) Received: from baygate.bayarea.net (baygate.bayarea.net [204.71.212.2]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id KAA00717 for ; Wed, 24 Jul 1996 10:01:33 -0700 (PDT) Received: (from mcnab@localhost) by baygate.bayarea.net (8.6.9/8.6.9) id JAA18900; Wed, 24 Jul 1996 09:54:47 -0700 Date: Wed, 24 Jul 1996 09:54:47 -0700 From: David McNab Message-Id: <199607241654.JAA18900@baygate.bayarea.net> To: dgy@rtd.com CC: paradox@pegasus.rutgers.edu, freebsd-questions@freebsd.org In-reply-to: <199607241343.GAA15489@seagull.rtd.com> (message from Don Yuniskis on Wed, 24 Jul 1996 06:43:20 -0700 (MST)) Subject: Re: your mail Reply-to: David McNab Sender: owner-questions@freebsd.org X-Loop: FreeBSD.org Precedence: bulk |> 2) if '.' appears as the very last entry in root's path is this |> still considered a security risk? I'm not so lazy that I'm not |> willing to type './command' as root--- just really curious about |> this type of stuff! | |I think the point of *forcing* you to type the "./" is hopefully a |reminder that you are executing an "alien" -- and potentially hostile |-- program. The only risk I can think of with "." at the end of the path is where a particularly devious attacker creates trojan horse "typos" and tries to catch you out. For example "lss" for ls(1) or some such. Or I suppose one could snoop through the administrator's "regular" account dot files to find his favorite aliases and shell functions, make trojan horse executables of the same name, then deliberately create a situation that would tempt the admin to use them. If like many people he (wisely) did not use aliases or shell functions as root, you might be able to catch him using one of them them out of habit. Neither of those seems very effective though, and they would be really easy to spot. Is there a sneakier scheme I'm not thinking of? In any case, I usually keep "." out of root's path and out of the system-wide defaults. But if a particular user wants to put "." at the end of the path, I really don't think it's a problem. In fact one could argue that it's better to put "." at the end of the default path for users, so that they don't add it themselves and put it at the beginning out of ignorance. -- Dave McNab