From owner-freebsd-security  Sun Jul 22 20:55: 7 2001
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Date: Sun, 22 Jul 2001 20:54:55 -0700 (PDT)
From: Matt Dillon <dillon@earth.backplane.com>
Message-Id: <200107230354.f6N3stj13517@earth.backplane.com>
To: "Jeroen Massar" <jeroen@unfix.org>
Cc: "'Brian Somers'" <brian@Awfulhak.org>,
	"'Hajimu UMEMOTO'" <ume@mahoroba.org>, <aschneid@mail.slc.edu>,
	<ras@e-gerbil.net>, <roam@orbitel.bg>,
	<freebsd-security@FreeBSD.ORG>, <freebsd-gnats-submit@FreeBSD.ORG>
Subject: Re: RE: bin/22595: telnetd tricked into using arbitrary peer ip 
References:  <000f01c11315$094851e0$420d640a@HELL>
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X-Loop: FreeBSD.org

    All very nice, guys, but not realistic.  Only FreeBSD uses an API.
    Third party programs access the structure directly for the most
    part so adding new fields to the structure will just cause more
    garbage to be written to the file (many third party programs 
    don't bother to bzero the structure before writing it out).  We 
    aren't going to add a separate hostname[] array... we just got
    through ripping out the hostname crap, because there was never 
    enough room in the field to actually store the FQDN, and many
    programs don't bother to verify the forward against the
    reverse anyway so the data would be suspect.  And short
    of making a 200+ character array to hold it, which would be masive
    bloat, there is no way to fit it in the structure.  If you want to store
    host names for posterity you will have to log-process the file and
    store the results somewhere else.  Every program under the sun assumes
    utmp is a fixed-length structure.

    Pretty much our only option is to extend the size of existing fields
    and take the 'oh hell the structure size changed' hit.

i						-Matt

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