It certainly is a serious threat, but given the amount of information available from Cisco you would think there would only be an extremely limited number of vulnerable systems. Most people should have patches in place before there are any exploits.
Vendors can take months to create patches, and sometimes users grumble about that, ... But the alternative is to have patches that can be circumvented or aren't appropriate for the vulnerability. It's a difficult balance.
Users should be less concerned if the application they're using is from a Linux distributor, because they have patches available. But with third-party vendors, users might not know about the problem until they read about it.