Security Holes . . . Who Cares?

We report on an observational study of user response following the OpenSSL remote buffer overflows of July 2002 and the worm that exploited it in September 2002. Immediately after the publication of the bug and its subsequent fix we identified a set of vulnerable servers. In the weeks that followed we regularly probed each server to determine whether its administrator had applied one of the relevant fixes. We report two primary results. First, we find that administrators are generally very slow to apply the fixes. Two weeks after the bug announcement, more than two thirds of the servers were still vulnerable. Second, we identify several weak predictors of user response and find that the pattern differs in the period following the release of the bug and that following the release of the worm.