Rule:
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Sid:
371

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Summary:
This event is generated when an ICMP echo request is made from a Cisco IOS 9.x system.

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Impact:
Information gathering.  An ICMP echo request can determine if a host is active.

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Detailed Information:
An ICMP echo request is used by the ping command to elicit an ICMP echo reply from a listening live host.  An echo request that originates from a system running Cisco IOS 9.x contains a unique payload in the message request.

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Affected Systems:
All

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Attack Scenarios:
An attacker may attempt to determine live hosts in a network prior to launching an attack.

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Ease of Attack:
Simple

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False Positives:
An ICMP echo request may be used to legimately troubleshoot networking problems.

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False Negatives:
None known.

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Corrective Action:
Block inbound ICMP echo requests.

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Contributors:
Original rule written by Max Vision <vision@whitehats.org>
Documented by Steven Alexander<alexander.s@mccd.edu>
Sourcefire Research Team
Judy Novak <judy.novak@sourcefire.com>

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Additional References:

Arachnids:
http://www.whitehats.com/info/IDS153

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