A critical vulnerability that was recently found in the low-level firmware of Lenovo ThinkPad systems also reportedly exists in products from other vendors, including HP and Gigabyte Technology.
An exploit for the vulnerability was published last week and can be used to execute rogue code in the CPU's privileged SMM (System Management Mode).
This level of access can then be used to install a stealthy rootkit inside the computer's Unified Extensible Firmware Interface (UEFI) -- the modern BIOS -- or to disable Windows security features such as Secure Boot, Virtual Secure Mode and Credential Guard that depend on the firmware being locked down.
The exploit, dubbed ThinkPwn, was released by a security researcher named Dmytro Oleksiuk last week without sharing it with Lenovo in advance. However, since then Oleksiuk has found the same vulnerable code inside older open source firmware for some Intel motherboards.
Lenovo said in a security advisory that the vulnerable code originated in a UEFI package provided to the company by one of its independent BIOS vendors (IBVs). These are companies that take the UEFI reference implementation and extend it, then sell the resulting package to PC manufacturers.