[4597] in bugtraq
Re: Killing NT 4.0's Name Server
daemon@ATHENA.MIT.EDU (Rubens Kuhl Jr.)
Wed May 28 00:08:06 1997
Date: Mon, 26 May 1997 22:17:22 -0300
Reply-To: "Rubens Kuhl Jr." <rkuhljr@PUERIDOMUS.BR>
From: "Rubens Kuhl Jr." <rkuhljr@PUERIDOMUS.BR>
X-To: Stefan Arentz <stefan.arentz@LUNA.NET>
To: BUGTRAQ@NETSPACE.ORG
Most NT 4.0 boxes doesn't listen to tcp port 19, chargen, unless the
administrator has installed "Small TCP/IP services" or such, which isn't a
default option.
But if MS DNS crashes just by sending a continuos stream of the ASCII set,
this can be easily done on a script, with no need to get it from the host
itself.
Workaround #1: block port tcp/53 on the security panel of TCP/IP. No more
zone transfers, no more TCP name resolutions (very rare), everyday UDP
resolution still works.
Workaround #2: filter port tcp/53 on the boundary router, allowing only
secondary servers to do zone transfers.
Workaround #3: install BIND.
Rubens Kuhl Jr.
----------
| $ telnet ntbox 19 | telnet ntbox 53
|
| Tested on NT 4.0 with service pack #3.
|
| Hello Dr. Watson, goodbye Mr. Nameserver.
