The OS X Mavericks 10.9.4 Update is recommended for all Mavericks users. It improves the stability, compatibility, and security of your Mac.
● Fixes an issue that prevented some Macs from automatically connecting to known Wi-Fi networks.
● Improves the reliability of wake from sleep.
● Includes Safari 7.0.5
For detailed information about this update, please visit: http://support.apple.com/kb/HT6281
For detailed information about the security content of this update, please visit: http://support.apple.com/kb/HT1222
You can install the update by selecting Software Update from the Apple menu at the top left of your screen.