From owner-freebsd-security  Mon Jul 23  9:13:53 2001
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Message-ID: <00e001c11393$37995340$0101a8c0@development.local>
From: "John Howie" <JHowie@msn.com>
To: "Matt Dillon" <dillon@earth.backplane.com>,
	"Garrett Wollman" <wollman@khavrinen.lcs.mit.edu>
Cc: <freebsd-security@FreeBSD.ORG>,
	<freebsd-gnats-submit@FreeBSD.ORG>
References: <000f01c11315$094851e0$420d640a@HELL><200107230354.f6N3stj13517@earth.backplane.com> <200107231538.f6NFcZl81468@khavrinen.lcs.mit.edu> <200107231557.f6NFvQb17025@earth.backplane.com>
Subject: Re: RE: bin/22595: telnetd tricked into using arbitrary peer ip 
Date: Mon, 23 Jul 2001 09:19:14 -0700
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This is getting off-topic for security but how about taking utmp and
implementing it as a device? I haven't sat down and thought it all through
but you could reasonably easily check the format of the data written to it
(or at least check the size) to determine how to handle it, and likewise for
the reads. That way you don't have to break your back trying to port all
those third party apps. A daemon could pick up the processed data and write
it to a log.

Even better, have the information validated in the kernel before being
logged. From a security perspective I have never liked the fact that crucial
log files can just be written to by any old app that happens to run in root
context.

john...


----- Original Message -----
From: "Matt Dillon" <dillon@earth.backplane.com>
To: "Garrett Wollman" <wollman@khavrinen.lcs.mit.edu>
Cc: <freebsd-security@FreeBSD.ORG>; <freebsd-gnats-submit@FreeBSD.ORG>
Sent: Monday, July 23, 2001 8:57 AM
Subject: Re: RE: bin/22595: telnetd tricked into using arbitrary peer ip


>
> :
> :<<On Sun, 22 Jul 2001 20:54:55 -0700 (PDT), Matt Dillon
<dillon@earth.backplane.com> said:
> :
> :>     All very nice, guys, but not realistic.  Only FreeBSD uses an API.
> :
> :Erm, no, wrong.
> :
> :SVR4 has an API.  This API is standardized as a part of the Austin
> :Group process.
> :
> :-GAWollman
>
>     Fine.. then if you want to get all the third party program authors to
>     use a magic API, be my guest.  Could it be, no... it couldn't...
>     all those programs couldn't just not *know* about the 'Austin Group
>     process' could they?  That's criminal!  Oops, oh well so much for
>     that!
>
>     Even ssh, about the closest third party program to BSD as there ever
>     was, doesn't use an API call for lastlog.  It does for utmp, sort-of,
>     but not for lastlog.  Bzzzt.
>
>     -Matt
>
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