Re: Enquiry on PCRE

[Alex Kirk <akirk () sourcefire com>]

It's anything except a ":" or a "?", 11 or more times, followed by ":/".
Note that the whole thing is anchored to the start of the URL by the
leading "^".

On Tue, Jun 19, 2012 at 11:08 PM, yew chuan Ong <yewchuan_23 () yahoo com>wrote:

> Hi Guys,
>
> I am kind of confuse with the pcre in this rule:
> pcre:"/^[^\x3a\x3f]{11,}\x3a\x2f/Usmi"
>
> alert tcp $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"WEB-MISC
> Checkpoint Firewall-1 HTTP parsing format string vulnerability attempt";
> flow:to_server,established; content:"|3A|/"; offset:11; http_uri;
> pcre:"/^[^\x3a\x3f]{11,}\x3a\x2f/Usmi"; reference:bugtraq,9581;
> reference:cve,2004-0039; reference:nessus,12084; classtype:attempted-admin;
> sid:2381; rev:15;)
>
> Does it mean that the payload should have ":?" appeared for at least 11
> times and following with ":/"?
> Thanks!
>
>
> Regards
> YC
>
>
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-- 
Alex Kirk
AEGIS Program Lead
Sourcefire Vulnerability Research Team
+1-410-423-1937
alex.kirk () sourcefire com

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Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
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threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/

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