Apple's Safari, released for the Windows platform in June 2007, is the second newest browser on Windows, behind Google's Chrome. (Naturally, Apple's browser also runs on OS X, and on iPhone and iPod Touch devices in a mobile edition.) Safari leads the pack in anti-phishing filtering and pop-up blocking, but it also has many security weaknesses.
Safari can be freely downloaded from Apple's Web site, and it is offered as an opt-in download option through Apple's Software Update program, which is installed with other Apple software, including iTunes and QuickTime. After Safari is installed, Software Update checks for Safari patches once a week using a Task Scheduler job.
[ See also the security reviews of Firefox, Internet Explorer, Google Chrome, and Opera. For more on browser security and protection against Web-borne threats, see the Security Adviser blog and "Test Center: Browser security tools versus the evil Web." ]
The Safari installer also installs a service called Bonjour, which allows Apple programs to advertise themselves and discover other Bonjour-compatible programs on the local network. Bonjour is used to automatically configure printers, hunt for file sharing opportunities, and find instant messaging peers, and it allows Safari to discover additional Web pages on the local network. In general, most security experts are wary of auto-discovery programs like Bonjour, and Bonjour itself has been involved in at least three known exploits. Bonjour is not essential to Safari's functionality and can be disabled.
The Safari executable is not User Account Control (UAC)-aware on Windows Vista computers, but Vista automatically elevates permissions for the install because the word "setup" is in the name (potentially, if Vista's heuristics detection functionality is disabled, the install could fail). On Windows Vista, Safari runs as a single process (Safari.exe) with DEP (Data Execution Prevention) disabled, a security negative shared only by Opera; ASLR (Address Space Layout Randomization) enabled; and file system and registry virtualization enabled, all with a MIC (Mandatory Integrity Control) level of Medium. In comparison, the rendering processes of both Internet Explorer and Google Chrome run with the more secure MIC setting of Low.