About Custom Vulnerability Signature

[KiCheon.Lee]

Hello,

My customer made vulnerability signature in FW. But FW doesn't detect this signature.

Customer Vulnerability Signature

context : http-req-message-body

pattern : eval\(gzinflate\(str_rot13\(base64_decode

I am searching this but I don't know.

So I need your assistance for it.

I have read Creating_Custom_Signatures-RevA.pdf document  

This document describe as the following message.

http-req-message-body

Description: Body content of a HTTP request when the body content cannot be recognized as URL encoded or MIME type data using the Content-type field.

Do you know to relate between not detecting signature and this description??

Thanks

[HITSSEC]

Cheon,

Can you get a pcap of the traffic flow including the pattern shown?  I am not aware of how this string is used?  (inbound to your servers of outbound from internal users) Also is the traffic encrypted? If so you wil need to decrypt it,

Phil