Zoom for Mac Entitlements

less than 1 minute read

Zoom for macOS versions < v4.6.9 had a very dodgy installer, detailed extensively by Patrick Wardle and by Felix Seele.

The app itself had entitlements to circumvent the hardened runtime on the Mac:

zoom entitlements screenshot

Per Patrick:

However the com.apple.security.cs.disable-library-validation entitlement is interesting. In short it tells macOS, “hey, yah I still (kinda?) want the “Hardened Runtime”, but please allow any libraries to be loaded into my address space” …in other words, library injections are a go!

Zoom responded fairly quickly with an update:

  • Resolved an issue where a malicious party with local access could tamper with the Zoom installer to gain additional privileges to the computer
  • Resolved an issue where a malicious party with local access could gain access to a user’s webcam and microphone

So now let’s check the entitlements again:

zoom entitlements screenshot

com.apple.security.cs.disable-library-validation is gone, closing the security hole.

I still don’t trust it, so will be checking out alternatives.