454.txt

snort入侵检测规则文件2.4 Snort是众所周知的网络入侵检测工具

Rule:

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Sid:
454

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Summary:
This event is generated when an ICMP Timestamp request is made with an invalid or undefined ICMP Code.

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

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Detailed Information:
An ICMP Timestamp request is used by the ping command to elicit an ICMP Timestamp reply from a listening live host.  This rule alerts on a generic ICMP request where no payload is included in the message or the payload does not match more specific rules. 

If ICMP type 8 (echo) traffic is filtered at a firewall, an attacker may try to use type 13 (timestamp) as an alternative.

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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 Timestamp request may be used to legitimately troubleshoot networking problems.

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False Negatives:
None known.

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Corrective Action:
Block inbound ICMP Timestamp requests.

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Contributors:
Original Rule Writer Unknown
Sourcefire Research Team
Nigel Houghton <[e-mail]>
Judy Novak <[e-mail]>
Additional information by Steven Alexander<[e-mail]>

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Additional References:


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