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Date: Mon, 28 Jul 1997 04:39:27 -0700 (PDT)
From: Vincent Poy <vince@mail.MCESTATE.COM>
To: Tomasz Dudziak <loco@onyks.wszib.poznan.pl>
cc: security@FreeBSD.ORG, "[Mario1-]" <mario1@PrimeNet.Com>,
        JbHunt <johnnyu@accessus.net>
Subject: Re: security hole in FreeBSD
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On Mon, 28 Jul 1997, Tomasz Dudziak wrote:

=)On Mon, 28 Jul 1997, Vincent Poy wrote:
=)
=)> Greetings,
=)> 
=)> 	We're had a hacker on two of our FreeBSD -current machines who
=)> hacked the machine as root.  
=)> 
=)> The symptoms are as follows:
=)> 1) User on mercury machine complained about perl5 not working which was
=)> perl5.003 since libmalloc lib it was linked to was missing.
=)> 2) I recompiled the perl5 port from the ports tree and it's perl5.00403
=)> and it works.
=)> 3) User hacks earth when he doesn't even have a account on the machine
=)> and can login to the machine remotely as root when rlogin and telnet
=)> wouldn't allow it.  
=)> 4) User is invisible in w, finger, who, users and can only be seen using
=)> ps -agux on a pty so I killed the process.
=)> 5) User changes hostnames even in a netstat output so it's all garbage
=)> 6) We went to inetd.conf and shut off all daemons except telnetd and 
=)> rebooted and user still can get onto the machine invisibly.
=)> 7) User shuts down the machine and changes root password
=)> 
=)> 	Saw the user on irc posting the password of earth with the login
=)> name root.  Any ideas?
=)
=)Well it is possible that he has recompiled /usr/bin/login for example.
=)Something like:
=)if(strcmp(username, "blahblah")==0)
=){
=)setuid(0);
=)setgid(0);
=)system("/bin/sh");
=)}
=)inserted does the job. You are then invisible to w and others... bot not
=)netstat i think...

	He wasn't invisible to netstat but he did do something that faked
the hostname even in netstat.

=)There was a security hole some time ago in perl that allowed local users
=)to gain root access... That's probably the way he got root access...
=)I would check my binaries, sup and recompile.

	Hmmm, I supped the perl from the most recent ports tree and also
all the binaries are about 2 months old from the -current tree.  I thought
the security hole was way before that.  What I didn't get is how did he
get access to the second system (earth) when he doesn't have a account
there in the first place?


Cheers,
Vince - vince@MCESTATE.COM - vince@GAIANET.NET           ________   __ ____ 
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