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From: Norman Wilson <norman@oclsc.org>
To: tuhs@tuhs.org
Subject: Re: [TUHS] Set-uid shell scripts
Date: Sun, 04 Aug 2019 17:18:45 -0400
Message-ID: <1564953528.6352.for-standards-violators@oclsc.org> (raw)

Noel Chiappa:

  I wonder why it passed the link name, instead of the actual filename of the
  target (script)? Perhaps to allow one script to have multiple functions,
  depending on the name it was called with?

====

In fact the latter is still used here and there in standard
system distributions.

But from a security viewpoint it doesn't matter.  For

	ln -s /bin/scriptname ./-i

substitute

	execl("/bin/scriptname", "-i", (char *)0);

If you can execute a program, you can fake its arguments,
including argv[0].  There is no defence.

Norman Wilson
Toronto ON

         reply index

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-04  7:36 Dave Horsfall
2019-08-04  7:43 ` Alec Muffett
2019-08-04 15:58   ` jnc
2019-08-04 16:30     ` Michael Kjörling
2019-08-04 16:48       ` Alec Muffett
2019-08-04 17:48         ` Michael Kjörling
2019-08-04 19:45           ` Alec Muffett
2019-08-04 16:50     ` Rico Pajarola
2019-08-04  7:46 ` arnold
2019-08-04 20:18 jnc
2019-08-04 20:29 ` Clem Cole
2019-08-04 20:42   ` Richard Salz
2019-08-04 23:58 ` Dave Horsfall
2019-08-04 21:18 Norman Wilson [this message]
2019-08-04 21:27 Norman Wilson
2019-08-06  8:28 ` jason-tuhs
2019-08-06  9:55   ` arnold
2019-08-06 22:48   ` Dave Horsfall
2019-08-06 22:56     ` ron minnich
2019-08-07  1:21     ` Dave Horsfall
     [not found]       ` <40c92e85142fe7e3@orthanc.ca>
2019-08-07 21:33         ` Dave Horsfall
2019-08-08  6:39           ` Peter Jeremy
2019-08-07 12:56     ` Chet Ramey
2019-08-07 21:40       ` Dave Horsfall
2019-08-08  5:16         ` Adam Thornton
2019-08-14  5:41           ` Efton Collins
2019-08-05  0:13 jnc

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