RE: Denial of Service Against pcAnywhere.

["Daniel Brandt" <daniel () netsight se>]

This is a known bug. It happens because PcAnywhere thinks you are trying to
connect, and when you don't continue, the unfinished connection just hangs
around waiting forever.. Restart the hosts (version 9.0 and above) by
telnetting to it on port 5631 and pressing enter when prompted..

see http://www.securityfocus.com/bid/1095 for more info on this..

/Daniel

-----Original Message-----
From: Vacuum [mailto:vacuum () technotronic com]
Sent: den 25 april 2000 23:40
To: bugtraq () securityfocus com
Cc: nmap-hackers () insecure org
Subject: Denial of Service Against pcAnywhere.


While performing a routine network audit, a TCP SYN scan caused
every pcAnywhere Host service on the network to stop responding.

The following versions were tested, other versions may be vulnerable as
well.

9.0.0 Build 133
9.2.0 Build 239
8.0.2 Build 220

Target Operating systems tested:
Windows NT Server Service Pack 6a -- Running 9.0.0 and 9.2.0 Versions
Windows NT Worksation Service Pack 5 Running 9.2.0 Version
Windows NT Server Service Pack 4  -- Running 8.0.2 Version


Using nmap version 2.30BETA21 (http://www.insecure.org/nmap)

Information gathering (Does not cause the crash)

nmap -sT -sU <target>

Servers running pcAnywhere version 8.x
show ports TCP 5631 and TCP 65301 open
           UDP 5632 and UDP 22    open

Servers running pcAnywhere version 9.x
show ports TCP 5631 and UDP 5632  open

nmap -sS <target> will cause the pcAnywhere Host Service to stop
responding until the service is stopped and restarted.

If anyone else could confirm or deny this it would be appreciated.

-vacuum
http://www.technotronic.com





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