Interscan VirusWall NT 3.23/3.3 buffer overflow.

[dspyrit () BEAVUH ORG (dark spyrit)]

A buffer overflow exists on the VirusWall smtp gateway - by sending a long
HELO command you can overflow the buffer and execute arbitrary code.

Example code has been written which will spawn a command prompt on a port
you specify.

Before you shrug this one off, take a look:

Connected to mail1.microsoft.com.
Escape character is '^]'.
220 mail1.microsoft.com InterScan VirusWall NT ESMTP 3.23 (build 9/10/99)
ready
at Sun, 07 Nov 1999 03:38:44 -0800 (Pacific Standard Time)

The ironic thing here is, VirusWall was designed to prevent viruses and
'malicious code'.

Obviously not a lot of thought was taken before laying their trust into
3rd party 'security' products.

A quick note to the millions out there who would give their right arm to
compromise microsofts network - sorry, their firewall would prevent the
payload from spawning a remote shell.. unless of course it was modified to
stop an existing service to open a port :)

Exploit source and binary is available at http://www.beavuh.org.

Credit to Liraz Siri for bringing this to our attention.

Hi to eEye/w00w00/teso.

dark spyrit
http://www.beavuh.org - bend over and pray.