The latest version of Apple's OS X is hit by a serious zero-day vulnerability that provides root privileges without the need for a password. This privilege escalation bug is being exploited and can be used to install malware on Macs. Full details at ARS Technica.
As Ars reported last week, the privilege-escalation bug stems from new error-logging features that Apple added to OS X 10.10. Developers didn't use standard safeguards involving additions to the OS X dynamic linker dyld, a failure that lets attackers open or create files with root privileges that can reside anywhere in the OS X file system. It was disclosed last week by security researcher Stefan Esser.
On Monday, researchers from anti-malware firm Malwarebytes said a new malicious installer is exploiting the vulnerability to surreptitiously infect Macs with several types of adware including VSearch, a variant of the Genieo package, and the MacKeeper junkware. Malwarebytes researcher Adam Thomas stumbled on the exploit after finding the installer modified the sudoers configuration file.