Kerio Personal Firewall Allows Remote Users to Cause a Protected Host to Crash
SecurityTracker Alert ID: 1005140|
SecurityTracker URL: http://securitytracker.com/id/1005140
(Links to External Site)
Date: Aug 27 2002
Denial of service via network|
Exploit Included: Yes |
A denial of service vulnerability was reported in the Kerio Personal Firewall software for Microsoft Windows operating systems. A remote user can cause a host protected by the firewall software to crash.|
NSSI-Research Labs warned that a remote user could cause the protected host's CPU utilization to reach 100%, even if the host's TCP/IP stack has been hardened.
It is reported that the firewall is vulnerable to SYN flood attacks. A remote user can send 300 or more TCP SYN packets to cause the target host to stop responding and the host to eventually crash.
If the firewall is set to block all services and protocols, a remote user can send 500 or more TCP SYN packets to cause the target host to stop responding and CPU utilization to reach 100%.
A remote user can cause CPU utilization to reach 100% or the protected target host to crash.|
No solution was available at the time of this entry.|
Vendor URL: www.kerio.com/us/kpf_home.html (Links to External Site)
Exception handling error, Resource error|
This archive entry has one or more follow-up message(s) listed below.|
Source Message Contents
Date: Mon, 26 Aug 2002 21:59:22 +0800|
Subject: Kerio Personal Firewall DOS Vulnerability
NSSI-Research Labs Security Advisory
Kerio Personal Firewall 2.x.x Denial of Service Vulnerability
Author: Abraham Lincoln Hao / SunNinja
e-Mail: email@example.com / SunNinja@Scientist.com
Advisory Code: NSSI-2002-keriopfw
Tested: Under Win2k Advance Server with SP3 / WinNT 4.0 with SP6a
Vendor Status: Vendor inform us to release new version and hopefully it would patch the vulnerability.
Vendors website: http://www.kerio.com
Kerio Personal Firewall (KPF) is a software agent that builds a barrier between your personal computer and the Internet. KPF
is designed to protect your PC against attacks from both the Internet, and other computers in the local network.
Kerio Personal Firewall 2.x.x for windows platform contains Denial of Service vulnerability. These vulnerability could allow
an attacker to hang-up the host and CPU utilization will hit up to 100%. Even if your hosts tcp/ip stack is hardened. .
[*Nix b0x with Synflooder] <===[10/100mbps switch===> [Host with KPF]
1] DoS vulnerability with Kerio Personal Firewall 2.x.x Default Installation
- KPF is vulnerable with Synflood attack by sending minimum of 300 syn packets the target host will stop from responding, 100%
of the CPU utilization will be consumed and eventually hangs-up the machine.
2] Setting the Personal firewall to High Security and Block all services and Protocols.
- It is quite similar to the first one but the personal firewall is configured to block all services and protocols. After sending
a minimum of 500 syn packets from port 1-1024. The host will stop from responding, 100% of the CPU utilization will be consumed.
1] Disable the Personal Firewall or Stop the KPF service. Wiindows with latest security patch or hotfix alone can handle 300-500
syn packets from a single host.
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