Swedish white-hat hacker Emil Kvarnhammar has discovered a critical vulnerability in Apple’s OS X Yosemite that gives hackers the ability to escalate administrative privileges on a compromised machine, and allows them to gain the highest level of access on a machine, known as root access. Once exploited, hackers could install malicious software or make other changes to your computer without any need of a password. The full disclosure of the bug will be made public in January 2015, as Apple needs some time to prepare a security patch.
Source: https://thehackernews.com/2014/11/rootpipe-critical-mac-os-x-yosemite.html