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CA-2003-04 MS-SQL Server Worm


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


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 -
VU#399260 -
VU#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

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

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:

CA-2002-22 -
VU#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


The CERT/CC is interested in receiving reports of this activity. If
machines under your administrative control are compromised, please
send mail to 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:

CERT/CC Contact Information

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

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Revision History
January 25, 2003: Initial release

Version: PGP 6.5.8


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