In Lenovo systems, SMM BIOS Write Protection is used to prevent writes to SPI Flash. While this provides sufficient protection, an additional layer of protection is provided by SPI Protected Range Registers (PRx). After resuming from S3 sleep mode in various versions of BIOS for some Lenovo ThinkPad systems, the PRx is not set. This does not impact the SMM BIOS Write Protection, which keeps systems protected.

The BIOS tamper detection mechanism was not triggered in Lenovo ThinkPad A285, BIOS versions up to r0xuj70w; A485, BIOS versions up to r0wuj65w; T495 BIOS versions up to r12uj55w; T495s/X395, BIOS versions up to r13uj47w, while the emergency-reset button is pressed which may allow for unauthorized access.

A potential vulnerability in the SMI callback function used in the Legacy SD driver in some Lenovo ThinkPad, ThinkStation, and Lenovo Notebook models may allow arbitrary code execution.

An internal shell was included in BIOS image in some ThinkPad models that could allow escalation of privilege.

The BIOS tamper detection mechanism was not triggered in Lenovo ThinkPad T495s, X395, T495, A485, A285, A475, A275 which may allow for unauthorized access.