BugTraq
Re: ZoneAlarm remote Denial Of Service exploit Sep 03 2003 07:43PM
Te Smith (tsmith zonelabs com)
In-Reply-To: <20030902145734.2258.qmail (at) sf-www3-symnsj.securityfocus (dot) com [email concealed]>

ZONE LABS SECURITY ADVISORY

DENIAL OF SERVICE REPORT

OVERVIEW

Zone Labs has found no evidence that, under real-world conditions, its

products are vulnerable to the Denial of Service attack described by

HackologyTeam (at) yahoo (dot) com [email concealed] at the BugTraq site and mailing list. There is

also no evidence that Zone Labs products are vulnerable to the similar

attack described by sprog (at) online (dot) ru [email concealed] in the follow-up post to BugTraq.

Date Published: September 3, 2003

EFFECT ON ZONE LABS USERS

Little or none.

ZONE LABS PRODUCTS

Zone Labs tests do not show that computers employing Zone Labs Integrity?,

ZoneAlarm® Pro, ZoneAlarm Plus, and ZoneAlarm security products are

vulnerable to this attack in real-world situations.

DESCRIPTION

This Denial of Service (DoS) attempt sends a barrage of UDP packets to a

PC protected with ZoneAlarm 3.7 or ZoneAlarm Pro 4.0. The vulnerability

reporter claims that this packet flood causes the target PC to hang. Zone

Labs' testing did NOT show this under real-world conditions (described

below). In the vulnerability report, the attacker included the Perl script

to launch the attack. Other important information, such as type of PC and

connection speed, was not specified.

IMPACT

Because the initial report lacked important information, Zone Labs tested

the Perl script on multiple PCs with a variety of network speeds. We were

unable to replicate the results the testers claim. We noted the following

results:

1) While we have seen a somewhat higher CPU usage and related slow-down on

the target machine, we have not seen anything resembling a DoS attack. The

largest slowdown occurred on a direct computer-to-computer 100-MBit

network. Even in that setup, we never observed a complete freeze under any

conditions. (Nor were other methods of UDP flooding effective.) For a

real-world DoS attack to succeed, it would need to be effective at much

slower connection speeds more typical for Internet connections (for

example, 1.5-MBit for a T1 or DSL connection).

2) Zone Labs Integrity, ZoneAlarm, ZoneAlarm Plus, and ZoneAlarm Pro were

not disabled as a result of the attacks, and the security of the test

machines was never compromised by the attempted DoS attack. Once the

attempted attacks stopped, the CPU usage went down to normal levels

immediately.

RECOMMENDED ACTIONS

Install any Zone Labs product to protect against UDP-flood attacks. Zone

Labs' tests did not show a Denial of Service result. We will be addressing

the relatively minor performance issues in upcoming releases. Note that in

the typical definition of a Denial of Service attack, the target is a

server PC (whose service is thus denied). ZoneAlarm, ZoneAlarm Plus, and

ZoneAlarm Pro are not designed to protect server platforms. The following

supported platform list applies to Zone Labs products:

http://www.zonelabs.com/store/content/support/znalmGeneralFAQ.jsp#9gener
al

RELATED RESOURCES

BugTraq posting: http://www.securityfocus.com/archive/1/335830/2003-08-

30/2003-09-05/0

CREDITS

This report first appeared on the BugTraq vulnerability list. Zone Labs

adheres to the vulnerability disclosure guidelines found at

http://www.wiretrip.net/rfp/policy.html. These guidelines specify

informing a vendor before public disclosure of a possible vulnerability,

so a security fix may be created to protect users before malicious

software takes advantage of the exploit. We encourage all vulnerability

reporters to follow the same procedure. To report a vulnerability, please

send an email to security (at) zonelabs (dot) com. [email concealed]

CONTACT

Zone Labs customers who are concerned about this issue or have additional

technical questions may reach our Technical Support group at:

http://www.zonelabs.com/store/content/support/support.jsp.

COPYRIGHT (c) 2003 by Zone Labs Incorporated

Permission to redistribute this alert electronically is granted as long as

it is not edited in any way unless authorized by Zone Labs. Reprinting the

whole or part of this alert in any medium other than electronically

requires permission from Zone Labs.

>

>

>

># Overview :

>#

># ZoneAlarm is a firewall software

># package designed for Microsoft Windows

># operating systems that blocks intrusion

># attempts, trusted by millions, and has

># advanced privacy features like worms,

># Trojan horses, and spyware protection.

># ZoneAlarm is distributed and maintained

># by Zone Labs.http://www.zonelabs.com

>#

># Details :

>#

># ZoneAlarm was found vulnerable to a

># serious vulnerability leading to a

># remote Denial Of Service condition due

># to failure to handle udp random

># packets, if an attacker sends multiple

># udp packets to multiple ports 0-65000,

># the machine will hang up until the

># attacker stop flooding.

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