Audio transcript

There are some readers here who will understand the import of the statement above and not believe it, and there are others who are not in a position to understand it all. For both camps, I’ll attempt to explain the details around what is (confirmed and corroborated by others) arguably one of the most critical security events to happen in the last decade of IT security.

What’s completely astonishing is the almost complete lack of media coverage (ARS Technica alone did a great piece) of this issue since its announcement by Kaspersky on the 27th of Dec 2023. Is this due to the holiday period (news of the original Meltdown and Spectre vulnerabilities was also released during the Dec/Jan holidays and seemed to have had a much greater reception in the media) or the fact that it’s Kaspersky (supposedly Russian-backed) that found and announced the issue?

No matter your thoughts on Kaspersky and its alleged ties to the Russian government, their research has been confirmed by others.

I reference information in this blog post from @sggrc’s Security Now 955 show as well as publicly available information from Kaspersky themselves and other 3rd parties/media.

Problem Statement

Kaspersky has found a hardware/silicon-based backdoor in 5 generations of Apple mobile silicon, starting with the A12 CPU (iPhone X) and continuing to the A16 CPU (iPhone 14/15). These CPUs have been used in other Apple products like the iPad, Watch and TV, so the iPhone is not the only affected product.

This backdoor allows complete remote access to, and control of, the affected devices … let that statement stew for a few minutes. And then understand that this allows a 3rd party to see and control anything on your Apple-based phone.

History

The issue now commonly referred to as CVE-2023-38606, was announced by Kasperky on Dec 27 2023. It refers to a hardware backdoor that was found in Apple CPUs designed and manufactured over a 5 year period. They state the following in their announcement:

The discovered vulnerability is a hardware feature, possibly based on the principle of “security through obscurity,” and may have been intended for testing or debugging. Following the initial 0-click iMessage attack and subsequent privilege escalation, the attackers leveraged this hardware feature to bypass hardware-based security protections and manipulate the contents of protected memory regions. This step was crucial for obtaining full control over the device. Apple addressed the issue, identified as CVE-2023-38606.

ARS Technica

Like Steve Gibson on the SN podcast, I take issue with Kaspersky’s characterisation of this being a vulnerability, which infers a bug as a result of a mistake in coding or design. To be very clear here, this backdoor was NO mistake – it was intentionally designed into the CPU.

Nonetheless, it does not diminish the severity of the issue.

So how did Kaspersky find this issue?

They had been following the propagation of Operation Triangulation, an APT (advanced persistent threat or complex malware that involves multiple stages of infection and attack using a variety of methods) which targets iOS devices through zero-click exploits distributed through iMessage. In other words, no action needs to be taken by the victim – they simply need to receive the attack message to be compromised. And this attack effects any Bionic CPU-based product from iPhones all the way to Apple Watches.

In the process of tracking the Triangulation malware (more details here), Kaspersky found that the method for the initial attack vector sourced from an undocumented hardware feature that few, if anyone, outside of Apple and chip suppliers such as ARM Holdings knew of.

There are 2 aspects of Triangulation to consider:

• how did the hardware backdoor come about?
• how did the attackers know about the backdoor and come to use it in their malware?

On the first question, It’s quite impossible for Apple to not have known about the backdoor in a CPU that their own engineers designe