Managing security on endpoint systems, even in mature organizations, is especially difficult, in part because the shape of the attack surface is different on every individual endpoint. Users often have the ability to change at least some of their endpoints’ security settings, as well as install software programs and browser plug-ins. The only safe conclusion that a security manager can arrive at is that many endpoints in their organizations are easily exploitable.
— excerpt from an upcoming book on stopping zero-day exploits
Peter H. Gregory 