• Print
  • Share
  • Dark

CVE-2007-2930: cryptographically weak DNS query IDs (BIND 8)

  • Updated on 27 Feb 2014
  • 3 minutes to read
  • Contributors

BIND 8 generates cryptographically weak DNS query IDs which could allow a remote attacker to poison DNS caches.


CVE-2007-2930   VU#927905

Posting date: 

29 Aug 2007

Program Impacted: 


Versions affected: 

All versions of BIND8






ISC BIND 8 generates cryptographically weak DNS query IDs which could allow a remote attacker to poison DNS caches.

This bug only affects outgoing queries, generated by BIND 8 to answer questions as a resolver, or when it is looking up data for internal uses, such as when sending NOTIFYs to slave name servers.

The DNS query id generation is vulnerable to analysis which provides a high chance of guessing the next query id. This can be used to perform cache poisoning by an attacker.

All users are encouraged to upgrade.


A remote attacker could predict DNS query IDs and respond with arbitrary answers, thus poisoning DNS caches.



Active exploits:

None known at this time.


                Upgrade or Patch

This issue is addressed in ISC BIND 8.4.7-P1, available as patch that can be applied to BIND 8.4.7.

The more definitive solution is to upgrade to BIND 9. BIND 8 is being declared "end of life" by ISC due to multiple architectural issues. Please see ISC's website at www.isc.org/sw/bind/bind8-eol.php for additional information and tools.

Note that BIND 8.x.x is End of Life as of August 2007.

Users who obtain BIND 8 from their operating system vendor should see the systems affected portion of this document for a partial list of affected vendors.

Acknowledgements: Thanks to Amit Klein from Trusteer (www.trusteer.com) for reporting this.

Related Documents:

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/support.

Do you still have questions?   Questions regarding this advisory should go to security-officer@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: https://www.isc.org/security-vulnerability-disclosure-policy

This Knowledge Base article https://kb.isc.org/article/AA-00922 is the complete and official security advisory document.

Legal Disclaimer: Internet Systems Consortium (ISC) is providing this notice on an "AS IS" basis. No warranty or guarantee of any kind is expressed in this notice and none should be implied. ISC expressly excludes and disclaims any warranties regarding this notice or materials referred to in this notice, including, without limitation, any implied warranty of merchantability, fitness for a particular purpose, absence of hidden defects, or of non-infringement. Your use or reliance on this notice or materials referred to in this notice is at your own risk. ISC may change this notice at any time.  A stand-alone copy or paraphrase of the text of this document that omits the document URL is an uncontrolled copy. Uncontrolled copies may lack important information, be out of date, or contain factual errors.

© 2001-2018 Internet Systems Consortium For assistance with problems and questions for which you have not been able to find an answer in our Knowledge Base, we recommend searching our community mailing list archives and/or posting your question there (you will need to register there first for your posts to be accepted). The bind-users and the dhcp-users lists particularly have a long-standing and active membership. ISC relies on the financial support of the community to fund the development of its open source software products. If you would like to support future product evolution and maintenance as well having peace of mind knowing that our team of experts are poised to provide you with individual technical assistance whenever you call upon them, then please consider our Professional Subscription Support services - details can be found on our main website.

Was this article helpful?