Apple is in the number one spot for the most bugs found in all of its products during the first half of 2010, ahead of Oracle, and Microsoft, according to Secunia (http://secunia.com/gfx/pdf/Secunia_Half_Year_Report_2010.pdf).
Trailing Apple in the top 10 are Oracle, Microsoft, HP, Adobe, IBM, VMWare, Cisco, Google and Mozilla. Secunia says their analysis supports the general perception that a high market share correlates with a high number of vulnerabilities. Apple (iTunes, Quicktime), Microsoft (Windows, Internet Explorer), and Sun Microsystems (Java, now part of Oracle) consistently occupy the top ranks during the last five years, with Adobe (Acrobat Reader, Flash) joining the group in 2008.
Secunia specializes in “vulnerability intelligence.” The company provides security advisories and information about patches, and provides software for vulnerability management.