Much ado has been made about whether or not Linux is truly more secure than Windows. We compared Windows vs. Linux by examining the following metrics in the 40 most recent patches/vulnerabilities listed for Microsoft Windows Server 2003 vs. Red Hat Enterprise Linux AS v.3:
1. The severity of security vulnerabilities, derived from the following metrics: 1. damage potential (how much damage is possible?) 2. exploitation potential (how easy is it to exploit?) 3. exposure potential (what kind of access is necessary to exploit the vulnerability?) 2. The number of critically severe vulnerabilities
The results were not unexpected. Even by Microsoft&#8217;s subjective and flawed standards, fully 38% of the most recent patches address flaws that Microsoft ranks as Critical. Only 10% of Red Hat&#8217;s patches and alerts address flaws of Critical severity. These results are easily demonstrated to be generous to Microsoft and arguably harsh with Red Hat, since the above results are based on Microsoft&#8217;s ratings rather than our more stringent application of the security metrics. If we were to apply our own metrics, it would increase the number of Critical flaws in Windows Server 2003 to 50%.
We queried the United States Computer Emergency Readiness Team (CERT) database, and the CERT data confirms our conclusions by a more dramatic margin. When we queried the database to present results in order of severity from most critical to least critical, 39 of the first 40 entries in the CERT database for Windows are rated above the CERT threshold for a severe alert. Only three of the first 40 entries were above the threshold when we queried the database about Red Hat. When we queried the CERT database about Linux, only 6 of the first 40 entries were above the threshold.