Re: NSSI-2002-zonealarm3: ZoneAlarm Pro Denial of Service Vulnerability

[Te Smith <tsmith () zonelabs com>]

In-Reply-To: <20021016144639.56762.qmail () mail com>

We have been unable to reproduce NSSI&#8217;s findings using the information 
they supplied.  We communicated our inability to verify the test results 
to NSSI and continue to test possible scenarios.

Bottom line:  
1)      The alleged behavior does not represent a security vulnerability. 
NSSI only alleges that under very limited circumstances involving a very 
heavy SYN flood with spoofed packets, a PC protected by ZoneAlarm Pro 
might slow down.
2)      None of the alleged behavior would put user data at risk.
3)      None of the alleged behavior would cause the protected PC to crash.
4)      This attack scenario is unrealistic because according to NSSI, it 
requires that the attack comes from within a LAN behind a &#8220;10/100mbps 
switch&#8221;. According to NSSI&#8217;s report, once the attack stops, the PC 
functions normally once again. Under almost all circumstances, a common 
Internet connection (dial-up, cable or DSL connection) does not have 
enough bandwidth to trigger this inconvenience. We did find some slow-down 
on very fast networks and will address these issues in our next product 
release.
5)      Our tests show that ZoneAlarm and ZoneAlarm Pro actually reduce 
the vulnerability to most DoS attacks significantly because our products 
prevent Windows from responding to this illegitimate traffic.
6)      Neither ZoneAlarm nor ZoneAlarm Pro are designed to protect server 
platforms.   The following supported platform list applies to both 
ZoneAlarm and ZoneAlarm Pro: 
http://www.zonelabs.com/store/content/support/znalmGeneralFAQ.jsp#9general
 
We appreciate NSSI&#8217;s efforts to track this issue and are looking forward 
to working with them as we have in the past.

Rgds, Te

Te Smith
Director, Corporate Communications
tsmith () zonelabs com
415-341-8233 (v)
415-341-8299 (f)