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Re: solaris tape dev permission stupidity
From: foobar () NULL NET (Michael R. Eckhoff)
Date: Thu, 22 Oct 1998 00:03:11 -0500

Along with MANY other problems.  I sent this into CERT and BSDi was also
contacted by a friend of mine about this over a month ago.  BSDi came back
and pretty much said that it was a sacrifice to make life easier on the
admin (I can quote the message if anyone cares to read it word for word),
which I was not very impressed with.  Now that this has been brought to
bugtraq (I was going to take it through CERT so the vendors could be
contacted first), most every commercial UNIX is setup this way.  The only
ones I could find that were not were the free unixes such as Slackware,
RedHat, *BSD, etc.  And I think think that Patrick Volkerding of Slackware
fame said it best when I asked him why he chose not to set the tape devices
this way with his reply of, "Common sense? :^)".

Please note as some of the other problems that can arise are that any user
can restore a protected password database as their own, mail spool files
that are not theirs, etc.  As I described it to one person, "Is your data
safe? Not if you back it up."  To expand on the mt erase problem, this with
a nice at or cron job could render your months worth of backups useless
since you'll be storing nothing but blank tapes and never even know it.

IMHO, if you want to keep the 'ease of use' for trusted users to access the
tape, create a new 'standard' group called 'tape' that gives full rights to
the tape devices, and make the trusted users newgrp tape before they access
it rather than open it up for everyone.

Michael R. Eckhoff                                              Paranet Voice: 972.239.5544
Sprint Paranet - CCL Dallas Hornets                             Project Voice: 972.652.2024
mreckhof () sprintparanet com                                            Parafax: 972.818.6374

-----Original Message-----
From: Bugtraq List [mailto:BUGTRAQ () netspace org]On Behalf Of joshua
Sent: Wednesday, October 21, 1998 5:15 PM
To: BUGTRAQ () netspace org
Subject: solaris tape dev permission stupidity


this is rather silly and obvious, but i couldn't find anything in seaching
the old archives on geek-girl.com.


under solaris, scsi tape devices (/dev/rmt/*, which are linked to
the st () x,x:
devs in /devices) are created with the permissions bits set to
666. this allows
a mallicious user with a login on your system to 'mt erase' the
contents of any
tape devices connected to your system.


this is a tough one. i'll let you figure it out yourself.


josh grubman / http://false.net/~jg
"if you don't ask, i won't upset you"

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