Forum Discussion

Eric_Weiss_2486's avatar
Eric_Weiss_2486
Icon for Nimbostratus rankNimbostratus
Feb 15, 2016

HTTP::header - match on 'Cookie' header entry

I'd like to use a rule to block client to REST server connections, as only server-to-server should be allowed for REST services. Does the following look sound? The idea is to block client connectio...
BIG-IP
iRules
security
Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Feb 15, 2016

Hi Eric,

you may try the syntax below, to "soft-block" the most common Browser-based User-Agents...

when HTTP_REQUEST {
    if { ( [HTTP::header value "User-Agent"] contains "Mozilla" ) or 
         ( [HTTP::header value "User-Agent"] contains "Opera" ) } then {
         reject
    }
}

Note: I've to second Kevin's opinion. Using such an ACL is more or less just providing Security-by-Obscurity... 😉

Note: Test the iRule carefully to not block legitimate API traffic. The chances are there, that a developer is using somehow a browser-based User-Agent string...

Cheers, Kai