Trend Micro researchers discovered a vulnerability that affects OS X below 10.11.3. It occurs by sending one special constructed IOConnectCallMethod requests to AppleGraphicsPowerManagement module. If an attacker sends a request once, Kernel memory heap corruption happens in method AppleGraphicsPowerManagement`AGPM:etBoost. As such, this would lead an attacker to execute arbitrary code with Kernel privileges.
While this vulnerability is not easy to exploit due to the lack of Kernel information leak and heap control, we recommend users to upgrade their OS X to latest version.