*BSD News Article 17350


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Path: sserve!newshost.anu.edu.au!munnari.oz.au!uunet!gatech!howland.reston.ans.net!agate!agate!usenet
From: ats@bsd386.first.gmd.de (Andreas Schulz)
Newsgroups: comp.os.386bsd.bugs,comp.os.386bsd.announce
Subject: security hole, crontab
Followup-To: comp.os.386bsd.bugs
Date: 20 Jun 1993 18:36:06 -0700
Organization: University of California, Berkeley
Lines: 27
Sender: cgd@agate.berkeley.edu
Approved: 386bsd-announce-request@agate.berkeley.edu
Message-ID: <3641@bigfoot.first.gmd.de>
NNTP-Posting-Host: agate.berkeley.edu
Summary: breakins possible
Keywords: security, alarm
Status: R

[ NOTE: a newer version of cron with this bug fixed (and more features)
	is available via anonymous-ftp from:
	    agate.berkeley.edu:pub/386BSD/386bsd-0.1/unofficial/newcron.tar.z
	    sun-lamp.cs.berkeley.edu:pub/misc/newcron.tar.z
	that's an archive to gunzip+untar from /usr/src, which replaces
	"libexec/crond" and "usr.bin/crontab".  recompile and install them,
	and this security hole will be gone.  -- cgd ]

I had just a breakin in my system from a normal user to
the superuser. This is on 386bsd0.1 with 0.2.3 patchkit applied,
if you are security aware, create a file "/var/cron/allow" and
put the users into it, that you also trust as superuser. Or change
the permissions of /usr/bin/crontab, remove the SUID bit on it.

I will give the details out of it in personal email, but not until
Tuesday evening/ Thursday morning, so what most administrators
had a chance to fix it first. And i am also not in town the next
days, and don't know if can read mail in the time between.

--
	  ATS ( ats@first.gmd.de or ats@cs.tu-berlin.de )

Andreas Schulz  GMD-FIRST     O-1199  Berlin-Adlershof  Rudower Chaussee 5
Gebaeude 13.7      Tel: +49-30-6392-1856	Germany/Europe
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