Mac OS X 10.7.3 was released yesterday with fixes to 51 vulnerabilities. Of the 51 total flaws, 40 were tagged by Apple with its usual 'arbitrary code execution' phrase, the company's way of saying that the bugs were critical and could be used by attackers to hijack a Mac with a working exploit. There are also DNS/AD fixes (this apparently fixes the SBS issues associated specifically with Lion). Other highlights included patching a vulnerability in SSL (secure socket layer) 3.0 and TLS (transport layer security) 1.0 and revocation of the Digicert certificates (this patch is very late considering this was patched in Windows as far back as September). There are also other OS fixes, including open-source elements that Apple integrates with its own code. Fixes affected the Apache, ColorSync, OpenGL, PHP and X11 components, among others.
UPDATE: In the past few hours many people have been updating to 10.7.3, but it does appear that Lion users have been suffering fatal system/application crashes. Some users claim that they have found the issue is linked to the installer, but this cannot be confirmed at this current time. We suggest if you do want to upgrade to 10.7.3 you use the Client Combo download.