ISC Security Advisory: Specially Crafted DNS Data Can Cause a Lockup in named
mcnally at isc.org
Tue Oct 9 21:15:16 UTC 2012
CVE-2012-5166: Specially crafted DNS data can cause a lockup in named
A nameserver can be locked up if it can be induced to load a specially
crafted combination of resource records.
Document Version: 2.0
Posting date: 9 October 2012
Program Impacted: BIND
9.2.x -> 9.6.x, 9.4-ESV->9.4-ESV-R5-P1, 9.6-ESV->9.6-ESV-R7-P3,
9.7.0->9.7.6-P3, 9.8.0->9.8.3-P3, 9.9.0->9.9.1-P3
If specific combinations of RDATA are loaded into a nameserver,
either via cache or an authoritative zone, a subsequent query
for a related record will cause named to lock up.
Please Note: All versions of BIND 9.2, 9.3, 9.4 and 9.5 are also
affected, but these branches are beyond their "end of life" (EOL)
and no longer receive testing or security fixes from ISC. For
current information on which versions are actively supported,
please see http://www.isc.org/software/bind/versions.
A nameserver that has become locked-up due to the problem reported
in this advisory will not respond to queries or control commands.
Normal functionality cannot be restored except by terminating
and restarting named.
This vulnerability can be exploited remotely against recursive
servers by inducing them to query for records provided by an
authoritative server. It affects authoritative servers if one
of the combinations of resource records is loaded from file,
provided via zone transfer, or submitted to a zone via dynamic
CVSS Score: 7.8
CVSS Equation: (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:
Setting the option 'minimal-responses' to 'yes' will prevent the lockup.
No known active exploits.
Upgrade to the patched version or new release most closely related
to your current version of BIND. The patched versions of BIND
and new releases can be downloaded from
BIND 9 version 9.7.7, 9.7.6-P4
BIND 9 version 9.6-ESV-R8, 9.6-ESV-R7-P4
BIND 9 version 9.8.4, 9.8.3-P4
BIND 9 version 9.9.2, 9.9.1-P4
ISC would like to thank Jake Montgomery of Dyn, Inc.
Document Revision History:
1.0 - 1 Oct., 2012 Advance Notification to Phase 1
1.1 - 8 Oct., 2012 Notification to Phase 3
2.0 - 9 Oct., 2012 Notification to Phase 4 (Public)
See our BIND Security Matrix for a complete listing of Security
Vulnerabilities and versions affected. If you'd like more
information on our Forum or product support please visit
www.isc.org/software/guild or www.isc.org/support.
Do you still have questions? Questions regarding this advisory
should go to security-officer at isc.org
Note: ISC patches only currently supported versions. When possible
we indicate EOL versions affected.
ISC Security Vulnerability Disclosure Policy: Details of our
current security advisory policy and practice can be found here:
The Knowledge Base article https://kb.isc.org/article/AA-00801
is the complete and official security advisory document. There
is also a summary article located on our website and linking to
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