[Air-l] windows security alert

[jeremy hunsinger]

usually I would not post these things to here, but this one is pretty 
significant.  If you are using windows, please find a way to ensure 
that this does not affect your system as soon as you can. I also 
realize that I am posting the USDHS version of the notice, if you want 
the Computer Emergency Response Team notice, which came out a few days 
before, that is available also.  If you do not know how to solve this 
problem on your Windows NT, 2000, XP, or Server machine yourself, it is 
advised that you email this to your local support group or system 
administrator to get their advice.

Thanks,
jeremy
---security notice follows---

Title: Potential For Significant Impact On Internet Operations Due To
Vulnerability In Microsoft Operating Systems (UPDATED)

Original Date July 24, 2003

Updated July 30, 2003

SYSTEMS AFFECTED:   Computers using the following operating systems:

	Microsoft Windows NT 4.0
	Microsoft Windows NT 4.0 Terminal Services Edition
	Microsoft Windows 2000
	Microsoft Windows XP
	Microsoft Windows Server 2003

OVERVIEW
THIS IS AN UPDATE TO THE DEPARTMENT OF HOMELAND SECURITY (DHS) JULY 24,
2003 ADVISORY ON MICROSOFT OPERATING SYSTEMS.  The DHS/ Information
Analysis and Infrastructure Protection (IAIP) National Cyber Security
Division (NCSD) is issuing this advisory in consultation with the
Microsoft Corporation to heighten awareness of potential Internet
disruptions resulting from the possible spread of malicious software
exploiting a vulnerability in popular Microsoft Windows operating
systems.

DHS expects that exploits are being developed for malicious use.
(UPDATE:  SEVERAL WORKING EXPLOITS ARE NOW IN WIDESPREAD DISTRIBUTION ON
THE INTERNET.  THESE EXPLOITS PROVIDE FULL REMOTE SYSTEM LEVEL ACCESS TO
VULNERABLE COMPUTERS.)  Two additional factors are causing heightened
interest in this situation:  the affected operating systems are in wide
spread use, and exploitation of the vulnerability could permit the
execution of arbitrary code.  DHS and Microsoft are concerned that a
properly written exploit could rapidly spread on the Internet as a worm
or virus in a fashion similar to Code Red or Slammer.  (UPDATE:  NO WORM
CODE HAS BEEN REPORTED; HOWEVER, AN INTERNET-WIDE INCREASE IN SCANNING
FOR VULNERABLE COMPUTERS OVER THE PAST SEVERAL DAYS REINFORCES THE
URGENCY FOR UPDATING AFFECTED SYSTEMS.)

IMPACT
The recently announced Remote Procedure Call (RPC) vulnerability in
computers running Microsoft Windows operating systems listed above could
be exploited to allow the execution of arbitrary code or could cause a
denial of service state in an unprotected computer.  Because of the
significant percentage of Internet-connected computers running Windows
operating systems and using high speed connections (DSL or cable for
example), the potential exists for a worm or virus to propagate rapidly
across the Internet carrying payloads that might exploit other known
vulnerabilities in switching devices, routers, or servers.

DETAILS
There is a vulnerability in the part of RPC that deals with message
exchange over TCP/IP. The vulnerability results from the handling of
malformed messages. This particular vulnerability affects a Distributed
Component Object Model (DCOM) interface with RPC, which listens on RPC
enabled ports. This interface handles DCOM object activation requests
that are sent by client machines (such as Universal Naming Convention
(UNC) paths) to the server. An attacker who successfully exploited this
vulnerability would be able to run code with local system privileges on
an affected system. The attacker would be able to take any action on the
system, including installing programs, viewing changing or deleting
data, or creating new accounts with full privileges.

RECOMMENDATION
Due to the seriousness of the RPC vulnerability, DHS and Microsoft
encourage system administrators and computer owners to take this
opportunity to update vulnerable versions of Microsoft Windows operating
systems as soon as possible.  Microsoft updates, workarounds, and
additional information are available at
http://microsoft.com/technet/treeview/default.asp?url=/technet/security/
bulletin/MS03-026.asp

DHS and Microsoft further suggest that Internet Service Providers and
network administrators consider blocking TCP and UDP ports 135, 139, and
445 for inbound connections unless absolutely needed for business or
operational purposes.

Advisories recommend the immediate implementation of protective actions,
including best practices when available.  DHS encourages recipients of
this advisory to report information concerning suspicious or criminal
activity to law enforcement or a DHS watch office.  The DHS Information
Analysis and Infrastructure Protection watch offices may be contacted
at:

For private citizens and companies - 	Phone: (202) 323-3205,
1-888-585-9078
            	Email: nipc.watch at fbi.gov
Online: http://www.nipc.gov/incident/cirr.htm
For telecommunications industry -     Phone:  (703) 607-4950
       		Email:  ncs at dhs.gov
For Federal agencies/departments -  	Phone: (888) 282-0870
           	Email:  fedcirc at fedcirc.gov
           	Online: https://incidentreport.fedcirc.gov

DHS intends to update this alert should it receive additional relevant
information, including information provided to it by the user community.
Based on this notification, no change to the Homeland Security Advisory
System level (HSAS) is anticipated; the current HSAS level is YELLOW.




jeremy hunsinger
jhuns at vt.edu
on the ibook
www.cddc.vt.edu
www.cddc.vt.edu/jeremy
www.cddc.vt.edu/jeremy/blog

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