BlackHat Asia 2019 presentation:
The complexity of x86-based systems has become so great that not even specialists can know everything. The recently discovered Meltdown/Spectre vulnerabilities, as well as numerous issues in Intel Management Engine, underscore the platform’s mindboggling intricacies. So, the chips manufacturer has to actively use of various means for manufacturing verification and post-silicon debugging. We found that modern Platform Controller Hub (PCH) and CPU contain a full-fledged logic signal analyzer, which allows monitoring the state of internal lines and buses in real time—a gold mine for researchers. A vulnerability previously discovered by us, INTEL-SA-00086, enabled studying this technology, which is called Intel Visualization of Internal Signals Architecture (VISA). We believe it is used for manufacturing line verification of chips. With an enormous number of settings, VISA allows for the creating of custom rules for capturing and analyzing signals. VISA documentation is subject to an NDA and not available to ordinary users. However, we will show how, with the help of publicly available methods, one can access all the might of this technology WITHOUT ANY HARDWARE MODIFICATIONS on publicly available motherboards. With VISA, we succeeded in partially reconstructing the internal architecture of PCH and, within the chip, discovered dozens of devices that are invisible to the user yet are able to access certain critical data. In our talk, we will demonstrate how to read signals from PCH internal buses (for example, IOSF Primary and Side Band buses and Intel ME Front Side Bus) and other security-sensitive internal devices.
Intel® Management Engine Critical Firmware Update (Intel SA-00086)
Intel Q3’17 ME 11.x, SPS 4.0, and TXE 3.0 Security Review Cumulative Update (INTEL-SA-00086)
Product family: Various
Impact of vulnerability: Elevation of Privilege
Severity rating: Important
Original release: Nov 20, 2017
Last revised: Nov 20, 2017
In response to issues identified by external researchers, Intel has performed an in-depth comprehensive security review of our Intel® Management Engine (ME), Intel® Server Platform Services (SPS), and Intel® Trusted Execution Engine (TXE) with the objective of enhancing firmware resilience. As a result, Intel has identified security vulnerabilities that could potentially place impacted platforms at risk. Systems using ME Firmware versions 11.0/11.5/11.6/11.7/11.10/11.20, SPS Firmware version 4.0, and TXE version 3.0 are impacted.[…]Based on the items identified through the comprehensive security review, an attacker could gain unauthorized access to platform, Intel® ME feature, and 3rd party secrets protected by the Intel® Management Engine (ME), Intel® Server Platform Service (SPS), or Intel® Trusted Execution Engine (TXE). This includes scenarios where a successful attacker could:
* Impersonate the ME/SPS/TXE, thereby impacting local security feature attestation validity.
* Load and execute arbitrary code outside the visibility of the user and operating system.
* Cause a system crash or system instability.
* External Security Researchers and Intel Validation.
* Intel would like to thank Mark Ermolov and Maxim Goryachy from Positive Technologies Research for working collaboratively with Intel on a coordinated disclosure for CVE-2017-5705.
Detection tool for Linux and Windows:
It is amazing to see the Intel ME research coming out of Positive Technologies!
From Google Translate:
JTAG in each house: full access via USB
Researchers at Positive Technologies have activated hardware debugging (JTAG) for Intel Management Engine, which allows full access to all PCH devices (Platform Controller Hub) using Intel DCI technology (via USB interface). We plan to share the details at one of the nearest conferences. And how to activate this interface, but for the main processor, we will tell below.[…]
Intel ME is the new “Pandora’s Box”, defenders are going to need bigger (better) tools… 😦
How to Hack a Turned-Off Computer, or Running Unsigned Code in Intel Management Engine
Intel Management Engine is a proprietary technology that consists of a microcontroller integrated into the Platform Controller Hub (PCH) microchip with a set of built-in peripherals. The PCH carries almost all communication between the processor and external devices; therefore Intel ME has access to almost all data on the computer, and the ability to execute third-party code allows compromising the platform completely. Researchers have been long interested in such “God mode” capabilities, but recently we have seen a surge of interest in Intel ME. One of the reasons is the transition of this subsystem to a new hardware (x86) and software (modified MINIX as an operating system) architecture. The x86 platform allows researchers to bring to bear all the power of binary code analysis tools. Unfortunately, this changing did not go without errors. In a subsystem change that will be detailed in the talk of Intel ME version 11+, a vulnerability was found. It allows an attacker of the machine to run unsigned code in PCH on any motherboard via Skylake+. The main system can remain functional, so the user may not even suspect that his or her computer now has malware resistant to reinstalling of the OS and updating BIOS. Running your own code on ME gives unlimited possibilities for researchers, because it allows exploring the system in dynamics. In our presentation, we will tell how we detected and exploited the vulnerability, and bypassed built-in protection mechanisms.
Intel ME is the new Pandora’s Box…