The report, from application security firm Cenzic, analyzed a number of Web security issues reported in the first half of this year. The browser comparison was only one part of the study, called, "Web Application Security Trends Report: Q1-Q2, 2009" (PDF download).
Firefox was the most vulnerable browser, logging 44 percent of the total vulnerabilities found, according to the report. Safari, at 35 percent, ranked next to Firefox at the bottom. IE had 15 percent of the vulnerabilities, and Opera only 6 percent.
Firefox, Microsoft's most robust rival in the browser market, reportedly has an estimated 330 million users and recently passed its fifth anniversary.
IE is still the most-used browser, followed by Firefox, Apple Safari, Google Chrome (which Cenzic didn't study) and Opera. GNC