CVE-2016-9147: An error handling a query response containing inconsistent DNSSEC information could cause an assertion failure bind

Michael McNally mcnally at isc.org
Wed Jan 11 22:35:25 UTC 2017


CVE:                    CVE-2016-9147
Document Version:       2.0
Posting date:           11 Jan 2017
Program Impacted:       BIND
Versions affected:      9.9.9-P4, 9.9.9-S6, 9.10.4-P4, 9.11.0-P1
Severity:               High
Exploitable:            Remotely

Description:

   Depending on the type of query and the EDNS options in the query
   they receive, DNSSEC-enabled authoritative servers are expected
   to include RRSIG and other RRsets in their responses to recursive
   servers.  DNSSEC-validating servers will also make specific
   queries for DS and other RRsets.  Whether DNSSEC-validating or
   not, an error in processing malformed query responses that
   contain DNSSEC-related RRsets that are inconsistent with other
   RRsets in the same query response can trigger an assertion
   failure.  Although the combination of properties which triggers
   the assertion should not occur in normal traffic, it is potentially
   possible for the assertion to be triggered deliberately by an
   attacker sending a specially-constructed answer.

Impact:

   This vulnerability occurs during the processing of an answer
   packet received in response to a query.  As a result, recursive
   servers are at the greatest risk; authoritative servers are at
   risk only to the extent that they perform a limited set of queries
   (for example, in order to do zone service - see
https://kb.isc.org/article/AA-00914).
   There are several variations of malformed query response that
   can cause an assertion failure, some of which will trigger a
   failure on recursive servers that are not DNSSEC-validating.

   Successful exploitation of this vulnerability will cause named
   to encounter an assertion failure and stop executing, resulting
   in denial of service to clients.

CVSS Score:             7.5
CVSS Vector:            CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

For more information on the Common Vulnerability Scoring System and
to obtain your specific environmental score please visit:
https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Workarounds:

   None known.

Active exploits:

   No known active exploits.

Solution:

   Upgrade to the patched release most closely related to your
   current version of BIND. These can all be downloaded from
   http://www.isc.org/downloads.

     BIND 9 version 9.9.9-P5
     BIND 9 version 9.10.4-P5
     BIND 9 version 9.11.0-P2

BIND Supported Preview Edition is a special feature preview branch
of BIND provided to eligible ISC support customers.

     BIND 9 version 9.9.9-S7

Document Revision History:

   1.0 Advance Notification, 03 January 2017
   1.1 Updated Versions affected to include 9.9.9-S6 and Solution to
include 9.9.9-S7, 09 January 2017
   2.0 Public Announcement, 11 January 2017

Related Documents:

   See our BIND9 Security Vulnerability Matrix at
   https://kb.isc.org/article/AA-00913 for a complete listing of
   Security Vulnerabilities and versions affected.

If you'd like more information on ISC Subscription Support and
Advance Security Notifications, please visit http://www.isc.org/support/.

Do you still have questions?  Questions regarding this advisory
should go to security-officer at isc.org.  To report a new issue,
please encrypt your message using security-officer at isc.org's PGP
key which can be found here:

https://www.isc.org/downloads/software-support-policy/openpgp-key/.

If you are unable to use encrypted email, you may also report new
issues at: https://www.isc.org/community/report-bug/.

Note:

   ISC patches only currently supported versions. When possible we
   indicate EOL versions affected.  (For current information on
   which versions are actively supported, please see
   http://www.isc.org/downloads/).

ISC Security Vulnerability Disclosure Policy:

   Details of our current security advisory policy and practice can
   be found here: https://kb.isc.org/article/AA-00861

This Knowledge Base article https://kb.isc.org/article/AA-01440 is
the complete and official security advisory document.

Legal Disclaimer:

   Internet Systems Consortium (ISC) is providing this notice on
   an "AS IS" basis. No warranty or guarantee of any kind is expressed
   in this notice and none should be implied. ISC expressly excludes
   and disclaims any warranties regarding this notice or materials
   referred to in this notice, including, without limitation, any
   implied warranty of merchantability, fitness for a particular
   purpose, absence of hidden defects, or of non-infringement. Your
   use or reliance on this notice or materials referred to in this
   notice is at your own risk. ISC may change this notice at any
   time.  A stand-alone copy or paraphrase of the text of this
   document that omits the document URL is an uncontrolled copy.
   Uncontrolled copies may lack important information, be out of
   date, or contain factual errors.

(c) 2001-2017 Internet Systems Consortium


More information about the bind-announce mailing list