When possible, Lenovo consolidates multiple BIOS security fixes and enhancements into as few updates as possible. The following list of vulnerabilities were reported by suppliers and researchers or were found during our regular internal testing. Not all products listed in the Product Impact section of this advisory were affected by every CVE summarized here.
The information has been provided by Avery Mosher
The original article can be found at:https://support.lenovo.com/us/en/product_security/LEN-30042
An internal shell was included in BIOS image in some ThinkPad models that could allow escalation of privilege.