Just as an add-on. As I was writing my first reply
to you I plugged in 205.188.180.57, just to make sure
it was the AOL site again. Right after, about 30
seconds or so, SonicWall sent me another FIN warning
concerning 205.188.180.57. So these sites are apparently
doing *some* kind of scan. Something I left off of
the other posts is that the scans originate from
port 80 of both of these machines.

This is what SonicWall has to say about FIN scans:
  It is possible that someone is scanning your IP 
address(es) with FIN packets looking for holes. 
The SonicWall is blocking these scans from getting 
to your servers. It is highly recommended that you 
contact your ISP to see if they can help you determine 
if this is indeed happening and hopefully put a stop to it.
  Also, there is a known issue that can cause the SonicWall 
to erroneously log FIN scans. Basically if multiple FIN packets 
are sent over a connection between a client and server the 
SonicWall might log a FIN scan. We're currently working on 
making the SonicWall less sensitive to this so as not to 
log false positives.

OK, fine I could see some situation where multiple FIN packets
might be sent during the course of an extended stay on a web
site. However I was only on the AOL site for two seconds. Now why,
out of the hundreds of web sites my users visit weekly, would 
just these two continuously trigger FIN scan alarms? I don't 
really believe it's anything malicious. But it is interesting. 

Jim Grossl
Boise, Idaho USA 

-----Original Message-----
From: Chris Hunt [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, March 19, 2002 6:13 AM
To: [EMAIL PROTECTED]
Subject: Re: [SonicWALL]- FIN scan false positives


Soooooooo what is the URL?  Would be interesting to see what happens for 
others and if it only applies to the XPRS2 or other models.

Chris


At 04:21 PM 03/18/2002 -0700, you wrote:
>  I get FIN scan alerts all the time from a particular
>web site that one of my users frequents. I had my user
>inform the site of this and their reply consisted of,
>1: Criticizing our ability to think because we use a
>SonicWall as a firewall.
>2: Telling us the SonicWall could not tell the difference

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