CVE-2007-2926: cryptographically weak query ids

AA-00921

The DNS query id generation is vulnerable to cryptographic analysis

Posting date: 
24 Jul 2007
Program Impacted: 
BIND
Versions affected: 
9.0 (all versions), 9.1 (all versions), 9.2.0, 9.2.1, 9.2.2, 9.2.3, 9.2.4, 9.2.5, 9.2.6, 9.2.7, 9.2.8, 9.3.0, 9.3.1, 9.3.2, 9.3.3, 9.3.4, 9.4.0, 9.4.1
Severity: 
Medium
Exploitable: 
Remotely

Description:

The DNS query id generation is vulnerable to cryptographic analysis which provides a 1 in 8 chance of guessing the next query id for 50% of the query ids. This can be used to perform cache poisoning by an attacker.

This bug only affects outgoing queries, generated by BIND 9 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.

All users are encouraged to upgrade.

Workarounds:

None.

Active exploits:

None known at this time.

Solution: 

Upgrade to BIND 9.2.8-P1, BIND 9.3.4-P1, BIND 9.4.1-P1 or BIND 9.5.0a6.

Acknowledgements: Amit Klein from Trusteer (www.trusteer.com) found this vulnerability.

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.

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-00921 is the complete and official security advisory document.

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