Zero-Day Advisory
Fortinet Discovers macOS QuartzCore Handling Shape Object Memory Corruption Vulnerability in CA::Render::Decoder::decode_shape
Summary
Fortinet's FortiGuard Labs has discovered a Memory Corruption vulnerability in macOS QuartzCore.QuartzCore, also known as CoreAnimation, is a framework used
by macOS and iOS to build an animatable scene graph. QuartzCore uses a unique
rendering model where the graphics operations are run in a separate process. On
macOS, the process is WindowServer. On iOS, the process is backboard. Both
of these process are out of sandbox and have the right to call setuid. The
service named com.apple.CARenderServer in QuartzCore is usually referenced as
CARenderServer. This service exists in both macOS and iOS and can be accessed
from the Safari Sandbox.
There exists a Memory Corruption vulnerability when
QuartzCore handles shape object in the function
CA::Render::Decoder::decode_shape(). It may lead to unexpected application
termination.
Solutions
Users should apply the solution provided by Apple.Timeline
Fortinet reported the vulnerability to Apple on January 3, 2019.
Apple confirmed the vulnerability on March 20, 2019.
Apple patched the vulnerability on March 25, 2019.