Friday, March 6th 2020
Researchers Find Unfixable Vulnerability Inside Intel CPUs
Researchers have found another vulnerability Inside Intel's Converged Security and Management Engine (CSME). For starters, the CSME is a tiny CPU within a CPU that has access to whole data throughput and is dedicated to the security of the whole SoC. The CSME system is a kind of a black box, given that Intel is protecting its documentation so it can stop its copying by other vendors, however, researchers have discovered a flaw in the design of CSME and are now able to exploit millions of systems based on Intel CPUs manufactured in the last five years.
Discovered by Positive Technologies, the flaw is lying inside the Read-Only Memory (ROM) of the CSME. Given that the Mask ROM is hardcoded in the CPU, the exploit can not be fixed by a simple firmware update. The researchers from Positive Technologies describe it as such: "Unfortunately, no security system is perfect. Like all security architectures, Intel's had a weakness: the boot ROM, in this case. An early-stage vulnerability in ROM enables control over the reading of the Chipset Key and generation of all other encryption keys. One of these keys is for the Integrity Control Value Blob (ICVB). With this key, attackers can forge the code of any Intel CSME firmware module in a way that authenticity checks cannot detect. This is functionally equivalent to a breach of the private key for the Intel CSME firmware digital signature, but limited to a specific platform."Every CPU manufactured in the last 5 years is subject to exploit, except the latest 10th generation, Ice Point-based chipsets and SoCs. The only solution for owners of prior generation CPUs is to upgrade to the latest platform as a simple firmware update can not resolve this. The good thing, however, is that to exploit a system, an attacker must have physical access to the hardware in question, as remote exploitation is not possible.
Discovered by Positive Technologies, the flaw is lying inside the Read-Only Memory (ROM) of the CSME. Given that the Mask ROM is hardcoded in the CPU, the exploit can not be fixed by a simple firmware update. The researchers from Positive Technologies describe it as such: "Unfortunately, no security system is perfect. Like all security architectures, Intel's had a weakness: the boot ROM, in this case. An early-stage vulnerability in ROM enables control over the reading of the Chipset Key and generation of all other encryption keys. One of these keys is for the Integrity Control Value Blob (ICVB). With this key, attackers can forge the code of any Intel CSME firmware module in a way that authenticity checks cannot detect. This is functionally equivalent to a breach of the private key for the Intel CSME firmware digital signature, but limited to a specific platform."Every CPU manufactured in the last 5 years is subject to exploit, except the latest 10th generation, Ice Point-based chipsets and SoCs. The only solution for owners of prior generation CPUs is to upgrade to the latest platform as a simple firmware update can not resolve this. The good thing, however, is that to exploit a system, an attacker must have physical access to the hardware in question, as remote exploitation is not possible.