Protecting websites from outdated browsers and plugins via a whitelist/blacklist combination?

Aside from using browser headers, I want to blacklist/whitelist browser and plugins from my site so that I can prevent these older unpatched systems from (1) being a general user of my site (2) removing those 'targets' from would-be-attackers reach.

My goal is to define some kind of endpoint security standard for 开发者_开发百科users who access my site, but without directly managing the environment, as they are customers.

Is there a standard way to use Whitelisting or Blacklisting to control browser access to my site?

For example, I want to prevent any browser that has outdated Flash, but I want to permit them if they have no Flash at all.

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You could use modernizr.com to detect the browser and features?