Denial-of-Service Vulnerability in ISC BIND 9
Last revised: Wed Sep 18 10:40:08 EDT 2002
A complete revision history can be found at the end of this file.
- 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.
OverviewA 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. DescriptionBIND 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 vulnerability.
This vulnerability is also being referenced as CAN-2002-0400:
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.
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 9.2.1.
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 comments.
In relation to this CERT advisory on security vulnerabilities with ISC BIND 9 implementation, Alcatel has conducted an immediate assessment to determine any impact this may have on our portfolio. An initial analysis has shown that none of our products is affected when used as delivered to customers. The security of our customers' networks is of highest priority for Alcatel. Therefore, investigations are going on, in particular for the UMTS GPRS Core Network portfolio, to determine any impact. Updates will be provided if necessary. Customers may contact their Alcatel support representative for more details.
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 investigating.
Caldera OpenLinux does not ship BIND9, and is therefore not vulnerable.
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 8.2.2-p5
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.
djbdns does not have this bug. Unlike BIND 9, djbdns does not commit
hara-kiri when an attacker tries to confuse it, or pokes it sharply, or
simply thinks bad thoughts in its general direction. djbdns has never
used any BIND-derived code. See http://cr.yp.to/djbdns.html .
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.
EDGE-FX contains a vulnerable version of BIND 9. Instructions for obtaining and installing a patch are available at ftp://ftp.f5.com/Domestic/Edgefx/named_patch/cert_patch_6_2002.html.
All other F5 Networks products contain BIND 8.2, 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 SECURITY BULLETIN: HPSBUX0207-202
Originally issued: 22 July 2002
HP Published Security Bulletin HPSBUX0207-202 with solutions for HP9000 Series 700/800 running HP-UX release 11.11 (11i) only with the BINDv920.INETSVCS-BIND fileset installed.
This bulletin is available from the HP IT Resource Center page at: http://itrc.hp.com "Maintenance and Support" then "Support Information Digests" and then "hp security bulletins archive" search for bulletin HPSBUX0207-202.
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.
Inktomi Inktomi Traffic Server DNS proxy does not include BIND9 and is therefore not vulnerable.
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 has reviewed the information and can confirm that our products are not affected by this vulnerability.
sent on June 3, 2002
* 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.
All NetApp products do not contain any BIND code, so no NetApp product is vulnerable to this problem.
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 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.
IRIX does not ship with BIND9 and is not vulnerable.
Sun does not ship BIND 9 with any version of Solaris at this time and is therefore not affected by this issue.
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.
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
Copyright 2002 Carnegie Mellon University.
June 04, 2002: Initial release June 11, 2002: Added vendor statement for djbdns June 11, 2002: Added vendor statement for Inktomi Corporation June 11, 2002: Updated vendor statement for F5 Networks, Inc. Aug 08, 2002: Added vendor statement for Hewlett Packard Sep 18, 2002: Added vendor statement for Alcatel