JavaScript to the operating system's API with superuser privileges. These flaws have affected major browsers including Firefox, Internet Explorer, and Safari. Plugins, such as video players, Adobe Flash, and the wide range of ActiveX controls enabled by default in Microsoft Internet Explorer, may also have flaws exploitable via JavaScript (such flaws have been exploited in the past). In Windows Vista, Microsoft has attempted to contain the risks of bugs such as buffer overflows by running the Internet Explorer process with limited privileges. Google Chrome similarly confines its page renderers to their own "sandbox". Web browsers are capable of running JavaScript outside
Internet Explorer 9 browser's ability to block malicious web pages or code. According to NSS, Internet Explorer 9 blocked 99% of malware downloads compared to 90% for Internet Explorer 8 that does not have SmartScreen Application Reputation feature. In early 2010, similar tests gave Internet Explorer 8 an 85% passing grade, the 5% improvement being attributed to "continued investments in improved data intelligence". By comparison, the same research showed that Chrome 6, Firefox 3.6 and Safari 5, which all rely on Google's Safe Browsing Service, scored 6%, 19% and 11%, respectively. Opera 10 scored 0%, failing to "detect any of the socially engineered