CVE-2016-9147: An error handling a query response containing inconsistent DNSSEC information could cause an assertion failure bind
mcnally at isc.org
Wed Jan 11 22:35:25 UTC 2017
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
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.
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
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:
No known active exploits.
Upgrade to the patched release most closely related to your
current version of BIND. These can all be downloaded from
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
See our BIND9 Security Vulnerability Matrix at
https://kb.isc.org/article/AA-00913 for a complete listing of
Security Vulnerabilities and versions affected.
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indicate EOL versions affected. (For current information on
which versions are actively supported, please see
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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.
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