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From: "H. Peter Anvin" <hpa@zytor.com>
To: Oleg Verych <olecom@flower.upol.cz>
Cc: "H. Peter Anvin (dash list)" <dash@vger.kernel.org>
Subject: Re: euidaccess() vs non suid /bin/sh (Re: dash test -w oddities)
Date: Wed, 30 Apr 2008 23:03:58 -0700	[thread overview]
Message-ID: <48195D4E.4020504@zytor.com> (raw)
In-Reply-To: <20080501001923.GS24008@flower.upol.cz>

Oleg Verych wrote:
> 
> Scripts with '#!/bin/sh' cannot be set-uid,
> 
> #man system (debian):
> 
>        Do  not  use  system()  from a program with set-user-ID or set-group-ID
>        privileges, because strange values for some environment variables might
>        be  used  to subvert system integrity.  Use the exec(3) family of func-
>        tions instead, but not execlp(3) or execvp(3).  system() will  not,  in
>        fact,  work  properly  from  programs  with set-user-ID or set-group-ID
>        privileges on systems on which /bin/sh is bash version 2, since bash  2
>        drops  privileges  on startup.  (Debian uses a modified bash which does
>        not do this when invoked as sh.)

This is largely considered a bug in bash, at least when invoked as /bin/sh.

	-hpa

  reply	other threads:[~2008-05-01  6:04 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-30 21:05 dash test -w oddities Remi Broemeling
2008-04-30 22:38 ` Oleg Verych
2008-04-30 23:01   ` euidaccess() vs non suid /bin/sh (Re: dash test -w oddities) Oleg Verych
2008-04-30 22:52     ` H. Peter Anvin
2008-05-01  0:19       ` Oleg Verych
2008-05-01  6:03         ` H. Peter Anvin [this message]
2008-05-02 16:48     ` Oleg Verych

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