Mac security researcher Patrick Wardle could gain root access to the macOS system via the Zoom software installer and found a security flaw that leaves the system open to viruses and ransomware. Wardle displayed the break-in at the Def Con hacking convention in Las Vegas. It works by utilizing the special permissions required to install or uninstall the Zoom installer. The security researcher circumvents user restrictions by using the installer’s auto-update feature, which must be executed in the background with specific rights.
This works since Zoom cryptographically signs each update and would only check for a signing certificate. Because of this, hackers might substitute a certificate with appropriate rights in its place, allowing it to carry on in the background. An attacker can run whatever virus they want by substituting a fraudulent certificate file for the valid one. A hacker can utilize the vulnerability to gain high-level root access from a position of limited system access, enabling them to alter and edit any file on the afflicted system.
Since most of the exploits were first identified, Zoom has released a fix, however, according to Wardle, the program still retains the superuser issue. Wardle had alerted Zoom to the issue in December, but Zoom’s fix introduced a new vulnerability that, with a little more work, a potential attacker might exploit. The more recent version of Zoom has another problem. We download and copy the installation package to the system administrator’s directory.
The file still has the same read/write rights as before because macOS is based on Unix. In a typical situation, this would mean that no user could access those files. This implies that if you are successful in opening the package, it can have been changed or tainted with malicious software.
