Apple has pushed out a slew of security updates for Macs running Snow Leopard (OS X 10.6) and Lion (OS X 10.7).
The operating system upgrades tackle various bugs that leak sensitive information, elevate a user's privileges and, most seriously, allow malicious code to be injected remotely and executed.
The 10.7.4 update grapples with a flaw in FileVault which causes users file encryption passwords to be stored in a log file in plain text. Apple's Remote Desktop client is also updated in 10.7.4 but isn't included in the update pack for Snow Leopard.
Mac OS X 10.7.4 fixes more than 30 vulnerabilities in the core OS, including Apple applications such as Quicktime, and some bundled software packages such as Samba, Ruby and PHP. A similar update for Snow Leopard 10.6.8 is available as Security Update 2012-0002.
Apple's explanation of the security components on both its Mac OS X updates can be found here. Each update requires a system restart to take effect, as is the norm.
The updates also bring in a new build of the Safari web browser. The latest version, 5.1.7, includes a feature that automatically disables the Adobe Flash browser plugin when it gets out of date and prompts users to install the latest version. This is to stop outbreaks of viruses that exploit security holes in old Adobe software.
Apple recently automatically switched off elderly Java installations in an OS update after hundreds of thousands of Macs were infected by the Flashback Trojan.
The desktop update follows hot on the heels of Apple's update for smartphones and tablets – iOS 5.1.1 – which was released earlier this week; that update addressed three vulnerabilities with updates to Safari and WebKit. ®