WASHINGTON DC ? Critics have taken aim at a study published by the U.S. Computer Emergency Readiness Team that said more vulnerabilities were found in Linux/Unix than in Windows last year.

The report, Cyber Security Bulletin 2005, was released last week. It claimed that out of 5,198 reported flaws, 812 were found in Microsoft’s Windows operating system, 2,328 were found in open-source Unix/Linux systems. The rest were declared to be multiple operating-system vulnerabilities, CNET.Com reported.

The report has attracted criticism from some in the open-source community. Linux vendor Red Hat said the vulnerabilities had been wrongly tagged, and so could not be used to compare the relative security of Windows and Linux/Unix platforms.

“The study is confusing and misleading. When you look at the list, the vulnerabilities are miscategorized,” Mark Cox, a consulting software engineer at Red Hat, said. “For example, Firefox is categorized as a Unix/Linux operating-system flaw, but it runs just as well on a Windows platform. Apache and PHP also run just as well on both platforms. There are methodological flaws in the statistics.”

In addition, Steven Christey, an editor for Common Vulnerabilities and Exposures, an organization that maintains a common vulnerability database, said that the statistics were no basis for comparison of the relative security of Windows and Linux/Unix, because they had been collected from different sources with different criteria for the collection of flaws.

CERT itself pointed out that the information in its bulletin “should not be considered the result of US-CERT analysis,” as it included information from outside sources.

Secunia thought that the nature of the reported vulnerabilities also made it difficult to compare security on the platforms, as Linux/Unix researchers concentrate on vulnerabilities in local privilege separation, while Windows researchers look at possible remote vulnerabilities.

The US-CERT study has also caused online debate within the open-source community. In Newsforge, the Linux and open-source online publication, Joe Brockmeier and Joe Barr cast doubt on the vulnerability totals.

Microsoft was not available for comment at the time of writing.