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Date: Mon, 23 Feb 2004 14:25:20 -0800
From: Tim Kientzle <tim@kientzle.com>
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Subject: Re: What to do about nologin(8)?
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John Baldwin wrote:
> 
> My point (sigh) is that doing system("logger") has the same problem set as 
> making nologin dynamic ...

No, it doesn't.  Not if you make nologin static and
have it create a fresh environment before running
any external programs.  This would also be considerably
more compact than statically linking in the logging functions.

> Also, personally, I would rather have nologin be static than fix the one 
> known case of login -p and just hope no other cases pop up in the future.  
> Call me paranoid. :)

Armoring nologin(8) is insufficient.

In particular, as David Schultz pointed out, there are a lot
of home-grown nologin scripts out there that are potentially
vulnerable regardless of what we do with the "official"
nologin program.

Tim Kientzle