[R]emoving administrator rights will better protect companies against the exploitation of:
- 90% of critical Windows 7 vulnerabilities reported to date
- 100% of Microsoft Office vulnerabilities reported in 2009
- 94% of Internet Explorer and 100% of Internet Explorer 8 vulnerabilities reported in 2009
- 64% of all Microsoft vulnerabilities reported in 2009
Initially I was pleased to read these results. Then I read BeyondTrust's methodology.
This report uses information found in the individual Security Bulletins to classify vulnerabilities by Severity Rating, Vulnerability Impact, Affected Software, as well as to determine if removing administrator rights will mitigate a vulnerability. A vulnerability is considered mitigated by removing administrator rights if the following sentence is located in the Security Bulletin’s Mitigating Factors section
Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights. (emphasis added)
"Could be less impacted?" In other words, BeyondTrust didn't do any testing. They just read Microsoft vulnerability reports, checked for that sentence, and published the results. I would be more comfortable with their conclusions if they conducted exploitation tests against suitable targets to determine if administrator rights made a difference or not.
This doesn't necessarily mean BeyondTrust is wrong. Removing administrator rights does help reduce exposures, but testing is required against modern exploitation methods to determine just how effective that countermeasure is.