Rule:

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Sid:
1616

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Summary:
This event is generated when an attempt is made to query version.bind on your DNS server.

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Impact:
Reconnaissance. This may indicate which version of BIND the server is running.

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Detailed Information:
An attacker can query a DNS server for the version of BIND running.  Some versions of BIND, by default, respond to these queries while BIND version 9; by default, does not.  A response to this query can assist an attacker in discovering servers that are potentially vulnerable to exploits associated with specific versions of BIND. 

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Affected Systems:
All versions of BIND.

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Attack Scenarios:
An attacker can execute this query to find DNS servers running specific versions of BIND.

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Ease of Attack:
Simple. Use the Unix command 'dig @ns.com version.bind txt chaos' 

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False Positives:
None Known

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False Negatives:
None Known

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Corrective Action:
Remove the ability to retrieve the version.bind chaos record via configuration options.

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Contributors:
Sourcefire Research Team
Brian Caswell <bmc@sourcefire.com>
Judy Novak <judy.novak@sourcefire.com>

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Additional References:

OSVDB:
http://www.osvdb.org/23

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