Apple has released Security Update 2010-003 (Leopard-Client) to address a critical vulnerability in the way Apple Type Services in Mac OS X 10.6 Snow Leopard parses embedded fonts. Users who view or download any documents containing maliciously crafted embedded fonts run a risk of arbitrary code execution. The update addresses this issue by improving index checking. This vulnerability was first demonstrated by Charlie Miller at the Pwn2Own conference 20 days ago, which shows a reasonably quick response on Apple's part. A nearly identical update - Security Update 2010-003 (Leopard-Server) - that eliminates the same vulnerability is available for Leopard Server. The update requires you are running Mac OS X 10.5.8 and is available via Software Update and the Apple Support Downloads page. (Free, 218.6/379.5 MB)
Viewing Wi-Fi Details in Snow Leopard
In Snow Leopard, hold down the Option key before clicking the AirPort menu. Doing so reveals additional technical details including which standards, speeds, and frequencies you're using to connect, as well as what's in use by other networks. With the Option key held down and with a network already joined, the AirPort menu reveals seven pieces of information: the PHY Mode, the MAC (Media Access Control) address, the channel and band in use, the security method that's in use, the RSSI (Received Signal Strength Indication) measurement, the transmit rate, and the MCS Index. In Leopard, some, but not all, of these details are revealed by Option-clicking the AirPort menu.