[VulnWatch] NSSI-2002-sygatepfw5: Sygate Personal Firewall IP Spoofing Vulnerability

From: Abraham Lincoln (sunninja@scientist.com)
Date: 09/16/02

From: "Abraham Lincoln" <sunninja@scientist.com>
To: bugtraq@securityfocus.com
Date: Mon, 16 Sep 2002 23:32:13 +0800

NSSI-Research Labs Security Advisory

http://www.nssolution.com (Philippines / .ph)
"Maximum e-security"


Sygate Personal Firewall 5.0 IP Spoofing Vulnerability

Author: Abraham Lincoln Hao / SunNinja

e-Mail: abraham@nssolution.com / SunNinja@Scientist.com

Advisory Code: NSSI-2002-sygatepfw5

Tested: Under Win2k Advance Server with SP3 / WinNT 4.0 with SP6a / Win2K Professional

Vendor Status: Vendor already accepted the vulnerability and they will be releasing new version to Patch the vulnerability

Vendors website: http://www.sygate.Com
Severity: High

     Sygate Personal Firewall 5.0 is a host-based Firewall designed to protect your PC against attacks from both the Internet, and other computers in the local network.

    Sygate Personal Firewall 5.0 for windows platform contains IP Spoofing vulnerability. These vulnerability could allow an attacker with a source IP of to Attack the host protected by Sygate Personal firewall without being detected. Sygate Personal firewall is having problem detecting incoming traffic with source ip (loopback address)

Test diagram:
   [*Nix b0x with IP Spoofing scanner / Flooder] <===[10/100mbps switch===> [Host with SPF] 
 1] IP Spoofing Vulnerability Default Installation

    - SPF is vulnerable with IP Spoofing attack by Scanning the host with a source ip address or network address The Attacker could scan or attack the target host without being detected by the personal firewall. This vulnerability is very serious w/c an attacker could start a Denial of Service attack against the spf protected host and launch any form of attack.
    - To those who wants to try to simulate the vulnerability, you may use source address - ;)


1] Set the SPF to BLOCK ALL mode setting which i don't think the user would do ;) This type of setting would block everything all incoming request and outgoing.

2] Block source address or network address manually in Advance rules section.

Any Questions? Suggestions? or Comments? let us know. (Free your mind)

e-mail: nssilabs@nssolution.com / abraham@nssolution.com / infosec@nssolution.com

   nssilabs team bring the heat! ;) Lawless the saint ;), dig0, b45h3r, jethro, mr. d.f.a, p1x3lb0y, rj45-gu1t4rgawd and to our webmaster raymund (R2/D2)

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