Overview of my favorite TCC bypass ever This vulnerability was disclosed at Black Hat Europe 2022 in the talk Knockout Win Against TCC - 20+ NEW Ways to Bypass Your MacOS Privacy Mechanisms. The technique used an old Launch Services function LSSetDefaultRoleHandlerForContentType that allowed (without any restrictions) to register arbitrary applications for handling specified UTI handlers. After the UTI handling app registration, the exploit simply opens juicy files (like AddressBook or iMessages database) and TCC happily grants access to them.

Overview These vulnerabilities were disclosed at Black Hat Europe 2022 in the talk Knockout Win Against TCC - 20+ NEW Ways to Bypass Your MacOS Privacy Mechanisms. The technique relied on an SQLite environment variable respected by libsqlite3.dylib which made apps using the standard SQLite system API log all the SQL queries. As such queries may contain sensitive user data normally protected by the TCC - I started researching all the problematic occurrences.

Overview These vulnerabilities were first disclosed at TyphoonCon in Seoul during my talk What happens on your Mac, stays on Apple’s iCloud?! Bypassing Mac privacy mechanisms. I found 2 code injection opportunities in iMovie and GarageBand which allowed me impersonating their com.apple.private.icloud-account.access entitlements. Then, I was able to talk to iCloud XPC helper which gave me the user’s iCloud tokens. With these tokens, I was able to get all the data that is synchronized with iCloud and is normally protected via TCC (Contacts, Reminders, Calendars, Location, etc).

Introduction This vulnerability has been disclosed on @Hack in Saudi Arabia in 20+ Ways To Bypass Your Macos Privacy Mechanisms presentation. In the end, it allowed impersonating TCC entitlements of any application installed on the device. Overview Applications may install privileged helpers in the /Library/PrivilegedHelpers directory. When such a helper tries to access the protected resource (e.g. Address Book), TCC tries to determine which app is responsible for the helper. If the main app is determined, TCC checks whether the app has proper permissions and grants the helper access to the protected resources.

Introduction This is the second TCC vulnerability that has been disclosed on my & Csaba’s talk “20+ ways to bypass your macOS privacy mechanisms” during Black Hat USA. This time by changing the NFSHomeDirectory variable I was able to bypass user TCC restrictions. Do you remember the CVE-2020–9934: Bypassing the macOS Transparency, Consent, and Control (TCC) Framework for unauthorized access to sensitive user data article describing a vulnerability found by Matt Shockley?

Introduction This vulnerability has been disclosed during my & Csaba’s talk “20+ ways to bypass macOS your privacy mechanisms” during Black Hat USA. It was a part of my COVID-19 lockdown research. 😉 In the end this vulnerability led to full TCC bypass as I was able to fully control the TCC database. How I found this vulnerability After the XPC research, I had an idea to verify if it will be possible to use the same tricks but on the macOS processes.

Summary This story is about an issue I reported in July of 2019 via Bugzilla. The ticket is public from the 16th of January 2020, so I don’t disclose any new vulnerability. However, I think such posts are necessary to show the community how applications installed on Macs may harm their privacy. This post will show you how an attacker that achieves code execution on your machine may use Firefox to abuse your Privacy preferences (TCC) and thus access your microphone/camera/location and record your screen.