Positive Technologies Security Advisory 2003-0307: DoS-attack in Kerio WinRoute Firewall

[Dmitry Maksimov <dmaksimov () ptsecurity ru>]

               Positive Technologies Security Advisory
                     http://www.ptsecurity.com


        Title: DoS-attack in Kerio WinRoute Firewall
         Date: March, 07 2003
     Severity: High
  Application: Kerio WinRoute Firewall 5.0.1
     Platform: Windows 95/98/ME/NT/2000/XP
Vendor Status: Notified, patched in version 5.0.2

 

I. DESCRIPTION 

---------------

Denial  of  Service  condition  exists  in Kerio WinRoute Firewall's Web
administration interface which hand service with 100% CPU utilization.


Positive  Technologies  reports that single simple HTTP request to Kerio
Winroute Firewall Web administration interface (TCP/4080)


GET / HTTP/1.0
Authorization: Basic XXX

 
instead of correct one:


GET / HTTP/1.0
Host: server
Authorization: Basic XXX


causes 100% CPU utilization of attacked computer.


II. IMPACT

---------------

Remote  user  can  launch denial of service attack against web interface
(port TCP/4080). Single request causes 100% CPU utilization. As a result
more  than  50%  of  future  connection  requests may be lost disturbing
normal functionality of the networking services.


III. SOLUTION 

---------------

Block TCP/4080 access or upgrade to Kerio WinRoute Firewall 5.0.2.


IV. VENDOR FIX/RESPONSE

---------------

Vendor was notified on 10.03.2003.


V. CREDIT

---------------

Positive Technologies is information security company especially focused on
protection of corporate networks from external attacks. The main trend of
PT’s activity is computer networks security audit and service. PT offers
wide range of services in the filed of information security: from network
architecture development or optimization to consulting and custom software
source-code examination.