[comp.unix.wizards] Serious potential security problem.

rickert@mp.cs.niu.edu (Neil Rickert) (05/01/91)

 Why are we worrying about somebody sneaking in through a tiny crack in the
basement, when the front door is swinging wide open.

  I just had the following experience:


	I logged into a system (with rlogin).  I was not asked for a password.

	The following are, I believe, the relevant facts:

	The system was a sun 4, running SunOS 4.1
	/etc/hosts.equiv contains the infamous '+' line.
	The sun is not running yp.
	The sun is not running a nameserver.
	There is no /etc/resolv.conf
	The host from which I logged in is not listed in /etc/hosts or .rhosts
	The 'who' command showed the numeric internet address of the host
		from which I logged in, not its name.
	The host from which I logged in is not on the same network.


 Face it.  That '+' in hosts.equiv is not safe now, never was safe, probably
never will be safe.  As long as vendors insist in this misfeature, TTY
problems seem unimportant by comparison.

-- 
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
  Neil W. Rickert, Computer Science               <rickert@cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115                                   +1-815-753-6940

stripes@eng.umd.edu (Joshua Osborne) (05/02/91)

In article <1991May1.140953.20081@mp.cs.niu.edu> rickert@mp.cs.niu.edu (Neil Rickert) writes:
>
> Why are we worrying about somebody sneaking in through a tiny crack in the
>basement, when the front door is swinging wide open.
[...]
> Face it.  That '+' in hosts.equiv is not safe now, never was safe, probably
>never will be safe.  As long as vendors insist in this misfeature, TTY
>problems seem unimportant by comparison.

Yes, but we aready fixed that, and I am sure many others have as well.  We
hadn't heard of the tty problems untill just recently (well, allright, I
had, I read it a while ago on comp.unx.wizards, and played with it on a
VAX, but I had assumed it was fixed by the time I became an admin.).  Just
because someone has a gun pointed to your head doesn't mean you can safely
ignore the one that is pointed at your heart...
-- 
           stripes@eng.umd.edu          "Security for Unix is like
      Josh_Osborne@Real_World,The          Multitasking for MS-DOS"
      "The dyslexic porgramer"                  - Kevin Lockwood
"CNN is the only nuclear capable news network..."
    - lbruck@eng.umd.edu (Lewis Bruck)

brnstnd@kramden.acf.nyu.edu (Dan Bernstein) (05/02/91)

In article <1991May1.140953.20081@mp.cs.niu.edu> rickert@mp.cs.niu.edu (Neil Rickert) writes:
>  Why are we worrying about somebody sneaking in through a tiny crack in the
> basement, when the front door is swinging wide open.
  [ ... ]
> 	/etc/hosts.equiv contains the infamous '+' line.

Sun makes lots of mistakes, and vendors who take ideas from Sun copy the
mistakes. However, relatively few Suns are multiuser machines; the
``tiny crack in the basement'' is in *everyone's* basement, not just
Sun's.

---Dan