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Date: Thu, 26 Feb 2004 09:30:04 -0600
From: "Jacques A. Vidrine" <nectar@FreeBSD.org>
To: kientzle@acm.org
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cc: freebsd-security@freebsd.org
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Subject: Re: Environment Poisoning and login -p
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On Wed, Feb 25, 2004 at 10:54:31AM -0800, Tim Kientzle wrote:
[...]
> Possible fix:  Have login unconditionally discard LD_LIBRARY_PATH
> and LD_PRELOAD from the environment, even if "-p" is specified.
[...]
> Possible fix: Eliminate the "-p" option to login.


I would prefer to redefine `-p' to mean, ``don't discard environmental
variables believed to be safe to propogate''.  We can start with this
list:

http://www.opengroup.org/onlinepubs/007904975/basedefs/xbd_chap08.html

plus

    EDITOR
    KRB5CCNAME
    LOGIN
    MAILDIR
    SSH_AGENT_PID
    SSH_AUTH_SOCK
    TERMCAP


If that is too draconian for you, then I guess just drop /LD_.*/.


Put the `environment cleaner' in libutil.

Cheers,
-- 
Jacques Vidrine / nectar@celabo.org / jvidrine@verio.net / nectar@freebsd.org