2018.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:
2018

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Summary:
This event is generated when a request is made to list remotely mounted Network File System (NFS) directories. 

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Impact:
Information disclosure.  This can allow an attacker to discover NFS file systems that have been mounted.

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Detailed Information:
The mountd Remote Procedure Call (RPC) implements the NFS mount protocol.  When an NFS client requests a mount of an NFS file system, mountd examines the list of exported file systems.  If the NFS client is permitted access to the requested file system, mountd returns a file handle for the requested directory.  An attacker or legitimate NFS client may request a list of mounted file systems.

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Affected Systems:
All systems running NFS.

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Attack Scenarios:
An attacker may attempt to list the mounted NFS file systems as a precursor to mounting them to read or change a specific file. 

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Ease of Attack:
Simple.   

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False Positives:
If a legitimate remote user is allowed to list mounted NFS file systems, this rule may trigger.

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False Negatives:
None Known.

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Corrective Action:
Limit remote access to RPC services.

Filter RPC ports at the firewall to ensure access is denied to RPC-enabled machines. 

Disable unneeded RPC services.

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Contributors:
Original rule written by Brian Caswell <[e-mail]>
Sourcefire Research Team
Judy Novak <[e-mail]>

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Additional References:


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