Secunia has found that the number of security bugs in the open source Red Hat Linux operating system and Firefox browsers far outstripped comparable products from Microsoft last year.

Out of the operating systems monitored by Secunia - Windows (98 and onwards), Mac OS X, HP-UX 10.x and 11.x, Solaris 8, 9, and 10 and Red Hat (excluding Fedora) - Red Hat was found to have by far the most vulnerabilities, at 633, with 99 percent found in third-party components. (Linux distributions are generally composed mostly of third-party software, which is integrated by the distributor.)

Red Hat has taken issue with the figures, claiming the accurate number should be 404 vulnerabilities for last year.

Windows had only 123 bugs reported, but 96 percent of those were found in the operating system itself.

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