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

AA-00922


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

Posting date: 
29 Aug 2007
Program Impacted: 
BIND
Versions affected: 
All versions of BIND8
Severity: 
Medium
Exploitable: 
Remotely

Description:

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.

Impact:

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

Workarounds:

None.

Active exploits:

None known at this time.

Solution: 

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.

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