As you may be aware York started experiencing intermittent network
connectivity problems around midnight. After several hours of
troubleshooting, NetOps staff determined that the problem
was related to a huge flood of traffic on port 1434/udp that
overloaded key network devices as well as a significant number of
servers on campus and around the world (see Chris Russel's note, as
well as a note from CERT below). Apparently a worm had been
released that exploited several known vulnerabilities in MS-SQL.
This worm compromised the vulnerable machines, and then caused these
computers to flood the network with traffic. It's probably
important to note that software patches that would have prevented
this problem have been available for a long time.
In order to stabilize the York network, NetOps staff had to block
all incoming and outgoing 1434/udp at our network border and
disabled network access for a number of compromised servers.
Unfortunately, it was necessary to shutdown almost all network
services in Atkinson College and Curtis/Central Square due to the
huge amount flood of traffic coming from those locations.
By 8:00am, NetOps staff had managed to stabilize most of the York
network, and had restored Internet/CA*Net connectivity. However
parts of Atkinson College, Curtis/Central Square, and Parking
Structure 2 were still off line. Working with local support groups,
and Information Security, stable network service was restored to
everywhere except portions of Curtis/Central Square by 2:00pm.
Service to the effected portions of Curtis/Central Square should be
restored shortly.
Unfortunately, the huge flood of network traffic generated by the
compromised computers and the resulting instability in the network
not only overloaded the network, but also overloaded a significant
number of servers on campus. If you are experiencing network
connectivity problems with servers or workstations at York, you
should completely reboot all of the computers in question.
People who are still having problems after following the various
instructions in this note can contact the CNS Helpdesk (voice:
416-736-5800, email: [log in to unmask]).
---------- Forwarded message ----------
Date: Sat, 25 Jan 2003 13:30:49 -0500
From: Chris Russel <[log in to unmask]>
To: [log in to unmask]
Subject: MS-SQL "saphine/slammer" worm
Resent-Subject: MS-SQL "saphine/slammer" worm
Network connectivity at York (and around the world) has been affected by a
new MS-SQL worm which spread rapidly starting sometime early this morning.
Several servers at York have been affected and have been isolated from the
network.
Preliminary analysis of the worm shows it is RAM-resident only and a
simple reboot will clear an infected system, although patches must be
applied to prevent rapid re-infection - affected servers should
disable the MS-SQL service temporarily, reboot, patch, and only then
re-enable the service.
MS technet advisory and patch:
http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS02-039.asp
MS-SQL service pack 3 will also patch the hole.
CNS will also be blocking the affected network port (1434/udp) to prevent
incoming attacks from outside York.
--
Chris Russel
Manager, CNS Information Security
York University, Toronto, Canada
[log in to unmask]
>From [log in to unmask] Sat Jan 25 14:11:28 2003
Date: Sat, 25 Jan 2003 12:01:32 -0500
From: CERT Advisory <[log in to unmask]>
To: [log in to unmask]
Subject: CERT Advisory CA-2003-04 MS-SQL Server Worm
-----BEGIN PGP SIGNED MESSAGE-----
CERT Advisory CA-2003-04 MS-SQL Server Worm
Original release date: January 25, 2003
Source: CERT/CC
A complete revision history can be found at the end of this file.
Systems Affected
* Microsoft SQL Server 2000
Overview
The CERT/CC has received reports of self-propagating malicious code
that exploits multiple vulnerabilities in the Resolution Service of
Microsoft SQL Server 2000. The propagation of this worm has caused
varied levels of network degradation across the Internet, in addition
to the compromise of vulnerable machines
I. Description
The worm targeting SQL Server computers is self-propagating malicious
code that most likely exploits two vulnerabilities in the Resolution
Service of Microsoft SQL Server 2000 vulnerabilities. The
vulnerability documented in VU#370308 allows the keep-alive
functionality employed by the SQL Server Resolution Service to launch
a denial of service against other hosts. Either the vulnerability
VU#399260 or VU#484891 allow for the execution of arbitrary code on
the SQL Server computer due to a buffer overflow.
VU#370308 - http://www.kb.cert.org/vuls/id/370308
VU#399260 - http://www.kb.cert.org/vuls/id/399260
VU#484891 - http://www.kb.cert.org/vuls/id/484891
Reports to the CERT/CC indicate that the high volume of 1434/udp
traffic generated between hosts infected with the worm targeting SQL
Server computers may itself lead to performance issues (including
possible denial-of-service conditions) on networks with infected
hosts.
Activity of this worm is readily identifiable on a network by the
presence of small UDP packets (we have received reports of 376-410
byte packets) from seemingly random IP addresses from across the
Internet to port 1434/udp.
II. Impact
Compromise by the worm indicates that a remote attacker can execute
arbitrary code as the local SYSTEM user on the victim system. It may
be possible for an attacker to subsequently leverage a local privilege
escalation exploit in order to gain Administrator access to the victim
system.
The high volume of 1434/udp traffic generated between hosts infected
with the worm may itself lead to performance issues on networks with
both infected and targeted, but non-vulnerable hosts.
III. Solution
Apply a patch
Administrators of all systems running Microsoft SQL Server 2000 are
encouraged to review CA-2002-22 and VU#370308 for detailed vendor
recommendations regarding installing the patch:
http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/bulletin/MS02-039.asp
CA-2002-22 - http://www.cert.org/advisories/CA-2002-22.html
VU#370308 - http://www.kb.cert.org/vuls/id/370308
Ingress/Egress filtering
The following steps are only effective in limiting the damage that can
be done by systems already infected with the worm. They provide no
protection whatsoever against the initial infection of systems. As a
result, these steps are only recommended in addition to the
preventative steps outlined above, not in lieu thereof.
Ingress filtering manages the flow of traffic as it enters a network
under your administrative control. Servers are typically the only
machines that need to accept inbound traffic from the public Internet.
In the network usage policy of many sites, external hosts are only
permitted to initiate inbound traffic to machines that provide public
services on specific ports. Thus, ingress filtering should be
performed at the border to prohibit externally initiated inbound
traffic to non-authorized services.
Egress filtering manages the flow of traffic as it leaves a network
under your administrative control. There is typically limited need for
machines providing public services to initiate outbound connections to
the Internet.
In the case of this worm, employing ingress and egress filtering can
help prevent compromised systems on your network from attacking
systems elsewhere. Blocking UDP datagrams with both source and
destination ports 1434 from entering or leaving your network reduces
the risk of external infected systems communicating with infected
hosts inside your network.
Recovering from a system compromise
If you believe a system under your administrative control has been
compromised, please follow the steps outlined in:
Steps for Recovering from a UNIX or NT System Compromise
http://www.cert.org/tech_tips/win-UNIX-system_compromise.html
Reporting
The CERT/CC is interested in receiving reports of this activity. If
machines under your administrative control are compromised, please
send mail to [log in to unmask] with the following text included in the
subject line: "[CERT#35663]".
_________________________________________________________________
Feedback can be directed to the author: Roman Danyliw
______________________________________________________________________
This document is available from:
http://www.cert.org/advisories/CA-2003-04.html
______________________________________________________________________
CERT/CC Contact Information
Email: [log in to unmask]
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
Postal address:
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
U.S.A.
CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) /
EDT(GMT-4) Monday through Friday; they are on call for emergencies
during other hours, on U.S. holidays, and on weekends.
Using encryption
We strongly urge you to encrypt sensitive information sent by email.
Our public PGP key is available from
http://www.cert.org/CERT_PGP.key
If you prefer to use DES, please call the CERT hotline for more
information.
Getting security information
CERT publications and other security information are available from
our web site
http://www.cert.org/
To subscribe to the CERT mailing list for advisories and bulletins,
send email to [log in to unmask] Please include in the body of your
message
subscribe cert-advisory
* "CERT" and "CERT Coordination Center" are registered in the U.S.
Patent and Trademark Office.
______________________________________________________________________
NO WARRANTY
Any material furnished by Carnegie Mellon University and the Software
Engineering Institute is furnished on an "as is" basis. Carnegie
Mellon University makes no warranties of any kind, either expressed or
implied as to any matter including, but not limited to, warranty of
fitness for a particular purpose or merchantability, exclusivity or
results obtained from use of the material. Carnegie Mellon University
does not make any warranty of any kind with respect to freedom from
patent, trademark, or copyright infringement.
_________________________________________________________________
Conditions for use, disclaimers, and sponsorship information
Copyright 2003 Carnegie Mellon University.
Revision History
January 25, 2003: Initial release
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