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CVE-2010-0097: BIND 9 DNSSEC validation code could cause bogus NXDOMAIN responses
Author: Cathy Almond Reference Number: AA-00932 Views: 13890 Created: 2013-05-23 22:23 Last Updated: 2013-05-23 22:23 0 Rating/ Voters

Posting date: 
19 Jan 2010
Program Impacted: 
Versions affected: 
9.0.x, 9.1.x, 9.2.x, 9.3.x, 9.4.0 -> 9.4.3-P4, 9.5.0 -> 9.5.2-P1, 9.6.0 -> 9.6.1-P2


There was an error in the DNSSEC NSEC/NSEC3 validation code that could cause bogus NXDOMAIN responses (that is, NXDOMAIN responses for records proven by NSEC or NSEC3 to exist) to be cached as if they had validated correctly, so that future queries to the resolver would return the bogus NXDOMAIN with the AD flag set.


This problem affects all DNSSEC-validating resolvers. It would be difficult to exploit due to other existing protections against cache poisoning (including transaction ID and source port randomization), but it could impair the ability of DNSSEC to protect against a denial-of-service attack on a secure zone.


None, administrators need to upgrade to one of the versions detailed below.

Active exploits:

None known at this time.


Upgrade BIND to one of the following: 9.4.3-P5, 9.5.2-P2 or 9.6.1-P3. There are no fixes available for BIND versions 9.0 through 9.3, as those releases are at End of Life. Note for BIND 9.7 beta-testers: pre-releases of 9.7.0 are vulnerable. Upcoming releases will include these patches.

Related Documents:

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

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Do you still have questions?  Questions regarding this advisory should go to

Note: ISC patches only currently supported versions. When possible we indicate EOL versions affected. 

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

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