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CA-2002-15 Denial-of-Service Vulnerability in ISC BIND 9


CERT Advisory CA-2002-15 Denial-of-Service Vulnerability in ISC BIND 9

Original release date: June 04, 2002
Last revised: --
Source: CERT/CC

A complete revision history can be found at the end of this file.

Systems Affected

* Domain Name System (DNS) servers running ISC BIND 9 prior to 9.2.1
Because the normal operation of most services on the Internet
depends on the proper operation of DNS servers, other services
could be affected if this vulnerability is exploited.


A denial-of-service vulnerability exists in version 9 of the Internet
Software Consortium's (ISC) Berkeley Internet Name Domain (BIND)
server. ISC BIND versions 8 and 4 are not affected. Exploiting this
vulnerability will cause the BIND server to shut down.

I. Description

BIND is an implementation of the Domain Name System (DNS) that is
maintained by the ISC. A vulnerability exists in version 9 of BIND
that allows remote attackers to shut down BIND servers. An attacker
can cause the shutdown by sending a specific DNS packet designed to
trigger an internal consistency check. However, this vulnerability
will not allow an attacker to execute arbitrary code or write data to
arbitrary locations in memory.

The internal consistency check that triggers the shutdown occurs when
the rdataset parameter to the dns_message_findtype() function in
message.c is not NULL as expected. The condition causes the code to
assert an error message and call abort() to shut down the BIND server.
It is also possible to accidentally trigger this vulnerability using
common queries found in routine operation, especially queries
originating from SMTP servers.

A vulnerability note describing this problem can be found at This vulnerability note
includes a list of vendors that have been contacted about this

This vulnerability is also being referenced as CAN-2002-0400:

II. Impact

Exploitation of this vulnerability will cause the BIND server to abort
and shut down. As a result, the BIND server will not be available
unless it is restarted.

III. Solution

Apply a patch from your vendor

The ISC has released BIND version 9.2.1. The CERT/CC recommends that
users of BIND 9 apply a patch from their vendor or upgrade to BIND

Appendix A. - Vendor Information

This appendix contains information provided by vendors for this
advisory. As vendors report new information to the CERT/CC, we will
update this section and note the changes in our revision history. If a
particular vendor is not listed below, we have not received their


The version of BIND that ships in Mac OS X and Mac OS X Server does
not contain this vulnerability.


Wind River Systems, Inc. does not include BIND 9 with any version
of BSD/OS.


SCO OpenServer from Caldera does not ship BIND9, and is therefore
not vulnerable.
Caldera Open UNIX does ship BIND9, and is vulnerable. We are
Caldera OpenLinux does not ship BIND9, and is therefore not

Compaq Computer Corporation

HP Alpha Server Products:
HP Tru64 UNIX:
Tru64 UNIX is not vulnerable to this reported problem. HP Tru64
UNIX ships with BIND 8.2.2-p5
TCP/IP for HP OpenVms:
TCP/IP for HP OpenVms is not vulnerable to this reported
problem.The current versions of TCP/IP for HP OpenVMS ship BIND
HP NonStop Server:
"HP NonStop Himalaya is not vulnerable to this problem. The
'named' function of Domain Name Server (T6021) which is implemented
for HP NonStop Himalaya is based on BIND 4.8. NonStop DNS is the
only Himalaya software product that includes 'named'."


Cray, Inc. is not vulnerable since the BIND distributed with Unicos
and Unicos/mk is not based on BIND 9.


Guardian Digital does not ship BIND 9 in any versions of EnGarde
Secure Linux, therefore we are not vulnerable. All versions were
shipped with BIND 8.

F5 Networks, Inc.

F5 Networks' products do not include BIND 9, and are therefore not
affected by this vulnerability.


The FreeBSD base system does not ship with ISC BIND 9. However, ISC
BIND 9 is available in the FreeBSD Ports Collection. It is
currently at version 9.2.1 and is therefore unaffected.

Hewlett-Packard Company

HP is Vulnerable, Solution investigation continuing..


After analysis of the affected component, IBM has determined that
the AIX bind deamon is not vulnerable to the attack as described in
the CERT advisory.

Internet Software Consortium

This vulnerability was found through routine bug analysis. BIND 9
is designed to exit when it detects an internal consistency error
to reduce the impact of bugs in the server. ISC strongly reccomends
that all BIND 9 users upgrade immediately to 9.2.1. BIND 9.2.1 can
be found at


Mandrake Linux 8.x ships with BIND9 and as such updated packages
will be available as early as possible.

Microsoft Corporation

Microsoft has reviewed the information and can confirm that our
products are not affected by this vulnerability.

NEC Corporation

sent on June 3, 2002
[Server Products]
* EWS/UP 48 Series operating system
- is NOT vulnerable.


NetBSD has not included Bind 9 in the base system of any release or
-current development branch.
Bind 9 is available from the 3rd party software system, pkgsrc.
Users who have installed net/bind9 or net/bind9-current should
update to a fixed version. pkgsrc/security/audit-packages can be
used to keep up to date with these types of issues.

Network Appliance

All NetApp products do not contain any BIND code, so no NetApp
product is vulnerable to this problem.

Nortel Networks Limited

Nortel Networks is reviewing its portfolio to determine if any
products are affected by the vulnerability noted in CERT Advisory
CA-2002-15. A definitive statement will be issued shortly.

Red Hat

Red Hat distributed BIND 9 in Red Hat Linux versions 7.1, 7.2, and
7.3. We are currently working on producing errata packages, when
complete these will be available along with our advisory at the URL
below. At the same time users of the Red Hat Network will be able
to update their systems using the 'up2date' tool.

Silicon Graphics, Inc.

IRIX does not ship with BIND9 and is not vulnerable.

Sun Microsystems

Sun does not ship BIND 9 with any version of Solaris at this time
and is therefore not affected by this issue.

SuSE, Inc.

We are affected by the bind9 DoS issue as well. All of our
currently supported SuSE Linux products come with a bind9 package.
We will release an announcement for the issue, coordinated with
your timeframe and not before we see your official announcement.

Unisphere Networks, Inc.

The Unisphere Networks ERX family of edge routers does not
implement a DNS server or named daemon within the Unison OS.
Additionally, the DNS client found on the ERX is not based on the
ISC BIND code. Unisphere Networks has no reason to expect a similar
problem exists in the DNS client implementation found on the ERX.

The CERT Coordination Center thanks the Internet Software Consortium
for notifying us about this vulnerability.

Author: Ian A. Finlay

This document is available from:

CERT/CC Contact Information

Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
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Copyright 2002 Carnegie Mellon University.

Revision History
June 04, 2002: Initial release

Version: PGP 6.5.8


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