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AUSCERT External Security Bulletin Redistribution
CVE-2016-2776: Assertion Failure in buffer.c While Building
Responses to a Specifically Constructed Request
28 September 2016
AusCERT Security Bulletin Summary
Publisher: Internet Systems Consortium
Operating System: UNIX variants (UNIX, Linux, OSX)
Impact/Access: Denial of Service -- Remote/Unauthenticated
CVE Names: CVE-2016-2776
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CVE-2016-2776: Assertion Failure in buffer.c While Building Responses to a
Specifically Constructed Request
Author: Brian Conry
Reference Number: AA-01419
Created: 2016-09-27 08:30
Last Updated: 2016-09-27 16:08
9.0.x -> 9.8.x, 9.9.0->9.9.9-P2, 9.9.3-S1->9.9.9-S3, 9.10.0->9.10.4-P2,
Testing by ISC has uncovered a critical error condition which can occur when a
nameserver is constructing a response. A defect in the rendering of messages
into packets can cause named to exit with an assertion failure in buffer.c
while constructing a response to a query that meets certain criteria.
This assertion can be triggered even if the apparent source address isn't
allowed to make queries (i.e. doesn't match 'allow-query').
All servers are vulnerable if they can receive request packets from any
CVSS Score: 7.8
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:C)
For more information on the Common Vulnerability Scoring System and to obtain
your specific environmental score please visit:
No practical workarounds exist.
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
BIND 9 version 9.9.9-P3
BIND 9 version 9.10.4-P3
BIND 9 version 9.11.0rc3
BIND 9 Supported Preview edition is a feature preview version of BIND provided
exclusively to eligible ISC Support customers.
BIND 9 version 9.9.9-S5
Document Revision History:
1.0 Advance Notification 2016-09-14
1.1 Added information about the Stable Preview release to versions affected.
Updated solution section to reflect replacing 9.11.0rc2 with 9.11.0rc3 and
9.9.9-S4 with 9.9.9-S5.
2.0 Posting date changed and public disclosure.
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/.
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