Apple update available for Mavericks (10.9.2)
If you’re running MacOS 10.9 (Mavericks), please run software update to get the latest version (10.9.2). Aside from some bugfixes (including improved Exchange interopability), this contains a fix for a serious security issue with SSL certificate validation.
This update was just released, and should be available via the App Store/Software Update. It can also be found at Apple’s support downloads page here: http://support.apple.com/downloads/