With the increase in macOS malware, Apple has been working hard in recent years to introduce layers of security that make it much more difficult for malicious software to run on Macs. However, both of them were bypassed thanks to a flaw in the operating system that was publicly revealed and fixed today.
Cedric Owens, a security researcher, found the flaw in mid-March while searching for ways to get around macOS defenses. Apple’s Gatekeeper system allows developers to register and pay a fee for their apps to run on Macs. All applications must also go through an automated vetting process as part of the company’s software notarization process.
The weakness is similar to a front door that is essentially barred and locked but has a cat door at the bottom through which you can easily throw a bomb. Apple made the mistake of assuming that applications would always have those characteristics. Owens found that if he created an app that was just a script—code that tells another program what to do instead of doing it—and didn’t have a regular application metadata file called “info.plist,” he could run it quietly on any macOS.The operating system refused to even acknowledge the most basic prompt: “This is an application downloaded from the Internet. Are you sure you want to open it?”