Latest version of Yosemite affected
The major vulnerability affects the latest version of
Worryingly, researchers from Malwarebytes have found a new installer that is exploiting this problem to infect Macs with the VSearch adware and the worst part about it is that attackers don't need a password to gain root permissions via a Unix shell.
Apple failed to patch up the flaw in the current 10.10.4 version of OS X, according to Stefan Esser, a security researcher, or a beta version of 10.10.5 tested by the same researcher, although the exploit doesn't work against 10.11, indicating Apple developers are working to eradicate it.
Wait for Apple's patch
Ridding your machine of the bug is currently quite difficult. The only fix right now comes in the form of a third-party patch produced by Esser himself and that in itself could come with a risk due to the fact it isn't made by Apple.
The best course of action is to hold fire until Apple issues a fix and in the mean time don't be alarmed as the exploit can only affect you if a faulty third-party program is present on your machine.