CVE-2014-8500: A Defect in Delegation Handling Can Be Exploited to Crash BIND
mcnally at isc.org
Mon Dec 8 17:13:06 UTC 2014
Failure to place limits on delegation chaining can allow an attacker
to crash BIND or cause memory exhaustion.
Document Version: 2.0
Posting date: 08 December 2014
Program Impacted: BIND 9
Versions affected: 9.0.x -> 9.8.x, 9.9.0 -> 9.9.6, 9.10.0 -> 9.10.1
By making use of maliciously-constructed zones or a rogue server,
an attacker can exploit an oversight in the code BIND 9 uses to
follow delegations in the Domain Name Service, causing BIND to
issue unlimited queries in an attempt to follow the delegation.
This can lead to resource exhaustion and denial of service (up
to and including termination of the named server process.)
All recursive resolvers are affected. Authoritative servers can
be affected if an attacker can control a delegation traversed
by the authoritative server in servicing the zone.
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 workarounds exist. Vulnerable versions of BIND 9 should be upgraded.
No known active exploits.
Upgrade to the patched release most closely related to your
current version of BIND. Patched builds of currently supported
branches of BIND (9.9 and 9.10) can be downloaded via
+ BIND 9 version 9.9.6-P1
+ BIND 9 version 9.10.1-P1
Regarding older versions:
BIND 9.6-ESV and BIND 9.8 have been officially designated "end
of life" (EOL) and no longer receive support. All organizations
running EOL branches should be planning transition to currently
supported branches. However, due to the severity of this
particular issue, source code diffs which can be applied to BIND
9.8 and BIND 9.6-ESV will be made available on request to
security-officer at isc.org.
ISC would like to thank Florian Maury (ANSSI) for discovering
and reporting this vulnerability.
Document Revision History:
1.0 Advance Notification: 20 November 2014
2.0 Public Disclosure: 08 December 2014
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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should go to security-officer at isc.org. To report a new issue,
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ISC patches only currently supported versions. When possible we
indicate EOL versions affected. (For current information on
which versions are actively supported, please see
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-01216 is
the complete and official security advisory document.
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