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

From: CERT Advisory (cert-advisory@cert.org)
Date: 06/04/02

Date: Tue, 4 Jun 2002 16:42:48 -0400 (EDT)
From: CERT Advisory <cert-advisory@cert.org>
To: cert-advisory@cert.org


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
   http://www.kb.cert.org/vuls/id/739123. 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 http://www.isc.org/products/BIND/bind9.html.


     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:

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   Revision History
June 04, 2002: Initial release

Version: PGP 6.5.8