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CVE-2013-4854: A specially crafted query can cause BIND to terminate abnormally
Author: Cathy Almond Reference Number: AA-01015 Views: 143551 Created: 2013-07-26 16:52 Last Updated: 2016-04-18 23:26 0 Rating/ Voters
A specially crafted query sent to a BIND nameserver can cause it to crash (terminate abnormally).

Document Version:          
Posting date: 
26 July 2013
Program Impacted: 
Versions affected: 
Open source: 9.7.0->9.7.7, 9.8.0->9.8.5-P1, 9.9.0->9.9.3-P1, 9.8.6b1 and 9.9.4b1; Subscription: 9.9.3-S1 and 9.9.4-S1b1


A specially crafted query that includes malformed rdata can cause named to terminate with an assertion failure while rejecting the malformed query.

BIND 9.6 and BIND 9.6-ESV are unaffected by this problem.  Earlier branches of BIND 9 are believed to be unaffected but have not been tested.  BIND 10 is also unaffected by this issue.

Please Note: All versions of BIND 9.7 are known to be 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


Authoritative and recursive servers are equally vulnerable.  Intentional exploitation of this condition can cause a denial of service in all nameservers running affected versions of BIND 9.  Access Control Lists do not provide any protection from malicious clients.

In addition to the named server, applications built using libraries from the affected source distributions may crash with assertion failures triggered in the same fashion.

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:


No known workarounds at this time.   

Active exploits:

Crashes have been reported by multiple ISC customers.  First observed in the wild on 26 July 2013.

Solution:  Upgrade to the patched release most closely related to your current version of BINDOpen source versions can all be downloaded from  Subscription version customers will be contacted directly by ISC Support regarding delivery.

  • BIND 9 version 9.8.5-P2
  • BIND 9 version 9.9.3-P2
  • BIND 9 version 9.9.3-S1-P1 (Subscription version available via DNSco)

Acknowledgements: ISC would like to thank Maxim Shudrak and the HP Zero Day Initiative for reporting this issue.

Document Revision History:

1.0 Phase One Advance Notification, 18 July 2013
1.1 Phases Two and Three Advance Notification, 26 July 2013
2.0 Notification to public (Phase Four), 26 July 2013

Related Documents:

Spanish Translation:  planned
Japanese Translation:
Portuguese Translation:

See our BIND Security Matrix for a complete listing of Security Vulnerabilities and versions affected.

This Knowledge Base article provides additional information and Frequently Asked Questions about this advisory.

If you'd like more information on our product support or about our Subscription versions of BIND, please visit

Do you still have questions?  Questions regarding this advisory should go to security-officer@isc.orgTo report a new issue, please encrypt your message using's PGP key which can be found here:  If you are unable to use encrypted email, you may also report new issues at:

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: ISC Software Defect and Security Vulnerability Disclosure Policy

This Knowledge Base article is the complete and official security advisory document.

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Feedback 8
  • #
    [thuiruiluon]: plz help me to reproduce this bug 2013-11-10 14:21

    Hi all, i can't reproduce ticket CVE-2013-4854 with above description. Please help me to reproduce this bug. Thanks all !

  • #
    [Cathy Almond]: Re: plz help me to reproduce this bug 2013-11-11 14:12

    Our policy is to provide publicly enough information for an organization to determine whether or not they might be vulnerable to a defect reported in a security advisory, but at the same time to avoid making available a recipe from which to exploit the vulnerability. We are therefore unable to give you any more information other than the details reported here and in the associated FAQ article, and the source code tarball that we recommend as the fix for the issue.

    We do also work more closely with our OEM partners and some of our subscription customers to help them determine specifically the risks to their production environments. For details of our subscription services and membership programs, see and If you might be interested in a formal relationship with us, please send us your details:

  • #
    [ jnduncan]: Please provide a CWE label 2013-09-05 19:30

    Could you please provide a CWE label for this issue? Thanks.

  • #
    [Cathy Almond]: Re: Please provide a CWE label 2013-09-25 22:01

    Thank you for asking - but we will not be assigning CWE labels at this time.

  • #
    [KB Admin]: No patch? 2013-08-12 11:43

    Thank you for your question. The patched versions of BIND are available directly from our website We do not ordinarily provide separate patches with the public announcement of a security issue; instead we offer full replacement versions of BIND for download.

  • #
    [KB Admin]: gpg signed tarballs 2013-08-12 11:40

    You didn't overlook how to download the signatures - the links to the signatures were not originally directly accessible from the downloads page on the website. We've updated the website so you should now see links to the signatures too when downloading the BIND tarball. Thanks for the feedback!

  • #
    [ sarnold]: gpg signed tarballs? 2013-07-26 21:48

    Did I overlook how to download the detached gpg signatures on the tarballs on the downloads page?


  • #
    [ sarnold]: No patch? 2013-07-26 21:37

    Did I overlook a link to a patch?


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