Re: SiD:4129 - No FP - No FN but wrong

[Joel Esler <jesler () sourcefire com>]

What rev of the rule are you running?  The copy I have (4) has a content match, two byte jumps and a byte_test.  Plus 
there is a specific port coded into it.  That's fairly specific, but I see how a FP would occur.

Do you have a pcap?

Joel

On Mar 28, 2011, at 11:08 AM, Crusty Saint wrote:

> Hi,
>
> For http://www.snort.org/search/sid/4129 "EXPLOIT Novell ZenWorks Remote Management Agent large login packet DoS 
> attempt" i see no false-positive or false-negative reported but there possibly could be one now. Though the 
> root-cause might well be PEBKAC.
>
> I think it is safe to assume such pebkac-positive would occur when a rule is active and applied on a network not 
> using the specified service/protocol but i also hope snort's logic is sufficiently precise to eliminate such erronous 
> detections.
>
> Based on what i've seen in the rule the detection is based on just two bytes so i assume the FP/FN rate to be much 
> higher (? help ?) if used on a network without related traffic present.
>
>
> Best Regards,
>
> Saint Crusty
>
>
> -- 
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Joel Esler
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