Apparently Apple faced another vulnerability of Gatekeeper technology that allows runing only trusted software on Mac computers.Security researcher Filippo Cavallarin discovered and in details described new vulnerability in macOS.
“On macOS X version 10.14.5 (Mojave) and below, it is possible to “easily bypass Gatekeeper in order to execute untrusted code without any warning or user’s explicit permission”, — Filippo Cavallarin said.
Gatekeeper checks Apple digital signature in Apple applications that uploaded not from official App Store. Respectively, if such signature not found, program does not start without users’ permission.However, integrated in system protection considers flash drives and network folders to be secure sources that do not need signature check. Attackers only have to force user to enable one of this resources for starting necessary application.
This can be done, for example, with the use of ZIP-file with the symbolic link that will indicate random location, and so, automatically mount a network resource. Simply speaking, user downloads archive, extracts content and follows the link to the “right” place from where any malicious executable file can be launched under the guise of a document or document folder.
“Now the victim is in a location controlled by the attacker but trusted by Gatekeeper, so any attacker-controlled executable can be run without any warning”, – Cavallarin states.
There’s a video here that shows the exploit in action:
This problem had to be fixed in macOS 10.14.5 as Filippo Cavallarin notified Apple about it on February 22. However, company ignored his messages. He finally published information about vulnerability after 90 days that Apple had to address this issue.