I suggest to use multi string signature for this request or meta signature.
I don't have acces to ips else I'll post the config.

On Saturday, August 18, 2012, Alexei Monastyrnyi wrote:

>  Yeah, the reason I was asking for a config is that I could not
> understand what type if engine Bruno was using.
>
> Bruno,
> you should be fine with TCP string engine catching that line. TCP string
> engine would try to match it across several IP packets. This is the major
> difference between atomic engines and string-like engines. In atomic one
> the string you match has to be in a single IP packet.
>
> Now, things which I can see go wrong are:
> -  you are not using TCP string engine
> - your regex is lame
> - you are trying to match traffic gong in the wrong direction. You shoudl
> match in direction from attacker to victim.
> - accordingly TCP port should be 23 TO the service
>
> Len us know how you go.
>
> HTH
> A.
>
>  On 8/19/2012 8:45 AM, Mike Rojas wrote:
>
>  I think this one depends so much in how the command is placed,
>
> Mainly because you can do sh run, show running-config, sh runn, etc. Now,
> I have seen that some types of telnet clients, send character per character
> making it difficult to the IPS
> to catch the string.
>
> My advice here, get and IP logging, open it with wireshark, see how the
> string is being sent and then create the string tcp signature.
>
> Mike.
>
>  ------------------------------
> Date: Sun, 19 Aug 2012 08:16:20 +1000
> From: [email protected] <javascript:_e({}, 'cvml',
> '[email protected]');>
> To: [email protected] <javascript:_e({}, 'cvml',
> '[email protected]');>
> CC: [email protected] <javascript:_e({}, 'cvml',
> '[email protected]');>
> Subject: Re: [OSL | CCIE_Security] IPS Question
>
> could you post your signature config in text?
>
>  On 8/18/2012 4:12 PM, Bruno Silva wrote:
>
> Hi Guys,
>
> I was studying some IPS functions and I came accross the regex session, which 
> is no news to me but, I was wondering if I had the following cenario:
>
> R1 ------ IPS ------ASA1
>
> Suppose I want to reset a telnet connection from R1 to ASA1 when the user 
> types show running-config how would I do that? I tried a lot of regular 
> expressions but I wasn`t able to do it...Mainly because when the user is 
> typping, it`s already sending the characters to the destination so if I do a 
> common regular expression the session is not reseted or I can just sneak a 
> way in to it doing stuff like typing show r and hitting "enter", comming back 
> to the previous string and completing it, or even worst, I can type (space) 
> show runn and it will still work. Can any of you guys think of a way of doing 
> it?
>
> If it was another device I would do this with expect, because I would expect 
> the prompt to change and then reset the connection, but I don`t think the 
> Cisco IPS has this function does it?
>
> What do you guys think?
>
> Thank you very much,
> Bruno.
> _______________________________________________
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>
> _______________________________________________ For more information
> regarding industry leading CCIE Lab training, please visit
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-- 
FNK, CCIE Security#35578
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