iOS 14 offers a new security system for “BlastDoor” messages

iOS 14 has added a new “BlastDoor” sandbox security system to iPhone and iPad to prevent attacks with the Messages app. Apple did not share information about the new security addition, but it was explained today by Samuel Groß, security researcher at Project Zero at Google, and highlighted by ZDNet.

Groß describes BlastDoor as a well-isolated service that is responsible for analyzing all reliable data in iMessages. A sandbox is a security service that executes code separate from the operating system, and it works in the Messages application.

BlastDoor takes a look at all incoming messages and inspects their contents in a secure environment, which prevents any malicious code inside a message from interacting with iOS or accessing user data.

As you can see, most of the reliable, reliable data processing has been moved to the new BlastDoor service. In addition, this design, with the 7+ services involved, allows the application of fine-grained sandboxing rules, for example, only the IMTransferAgent and apsd processes are required to perform network operations. As such, all services in this pipeline are now properly restricted (BlastDoor service being probably the most powerful).

The feature was designed to counter specific types of attacks, such as those in which hackers used shared cache or brute force attacks. As ZDNet He points out that security researchers have found in recent years errors in the execution of the iMessage remote code that could allow an iPhone to infiltrate only with text, which BlastDoor should address.

Groß found the new OSiOS 14‌ feature after investigating a message hacking campaign targeting Al Jazeera journalists. The attack did not work in OSiOS 14‌ and the investigation of what led to the discovery of BlastDoor.

According to Groß, the Apple BlastDoor changes are “close to the best that could have been made, given the need for compatibility with previous versions” and will make the iMessage platform much more secure.

This blog post discussed three improvements to îniOS 14‌ that affect iMessage security: the BlastDoor service, redistribution of shared cache, and exponential limitation. In general, these changes are probably very close to the best that could have been made, given the need for compatibility with previous versions and should have a significant impact on the security of iMessage and the platform as a whole.

It’s great to see Apple setting aside resources for these types of major refactoring to improve end-user security. Moreover, these changes also highlight the value of offensive security work: not only have bugs been fixed, but structural improvements have been made based on information obtained from the development of development works.

Those interested in the full summary of how BlastDoor works can visit the Project Zero blog post on this topic.