I want to Block A URL for my web application when it contains the following parameters

try this

when HTTP_REQUEST {
    if {[HTTP::query] contains "%3C" | [HTTP::query] contains "\$" | [HTTP::query] contains "%24"} {
        HTTP::respond 403 content {Content Rejected}
    }
}

Here is a nice article on using ASM to use parameters to block a URL:

http://www.thef5guy.com/blog/2011/05/big-ip-asm-using-parameters-to-block-attacks/

Hi,

I know this is in LTM, but If you have ASM, I believe u/dakritt answered this question a while back in the link below: https://devcentral.f5.com/questions/asm-disallowed-url-and-wildcard-58982

You can use ASM to create an attack signature and block that, if those parameters are being sent as part of a user's request.