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- Path: sparky!uunet!mcsun!news.funet.fi!news.cs.tut.fi!hmj
- From: hmj@cs.tut.fi (J{rvinen Hannu-Matti)
- Newsgroups: comp.security.misc
- Subject: Re: Setuid script - is this unsecure?
- Date: 23 Nov 1992 09:34:05 GMT
- Organization: Tampere University of Technology
- Lines: 26
- Distribution: world
- Message-ID: <1eq8idINNof0@cs.tut.fi>
- References: <AMOSS.92Nov6102549@shuldig.cs.huji.ac.il> <1eg5tmINN9eh@cs.tut.fi> <1992Nov20.135059.24347@fwi.uva.nl>
- NNTP-Posting-Host: kuukkeli.cs.tut.fi
-
- >>Equivalent would be that you let anybody execute mount (i.e., set
- >>mount suid), which is not reasonable. Also you have to deny suid
- >>programs on the floppy, and ensure that there does not exist special
- >>devices on the floppy.
-
- >>I've written a set of programs (fdmkfs, fdmount, and fdumount) to give
- >>users access to the floppy. They are available by anonymous ftp on
- >>site cs.tut.fi (130.230.4.2), file pub/src/tut/floppy.shar. Use on
- >>your own risk.
-
- >Everybode executing mount isn't indeed a good idea:
- >How about mount /dev/fd /etc
-
- That's exactly what I meant - perhaps I was not too clear. The orignal
- C-code above lets anybody to execute mount as a suid-program, which is
- equivalent to set mount suid.
-
- My set of programs mount /dev/fd0c always on /floppy/disk to avoid
- such problems. They also set privileges of /dev/fd0* and
- /dev/rfd0* to prevent creation of devices using editors after the
- mount.
- --
- -----
- Hannu-Matti Jarvinen, hmj@cs.tut.fi
- Opinions of tut != opinions of mine, and vice versa.
- TTKK on samaa mielt{ kanssani siit{, ett{ en edusta sen mielipidett{.
-