Lenovo has issued a security advisory disclosing three (3) medium severity vulnerabilities tracked as CVE-2022-1890, CVE-2022-1891, and CVE-2022-1892. The UEFI firmware used in several laptops manufactured by Lenovo is vulnerable to three (3) buffer overflow vulnerabilities that, if exploited, could enable attackers to hijack the startup routine of Windows installations. The first flaw is an issue in the ReadyBootDxe driver used in some Lenovo notebook products. The additional two (2) flaws are buffer overflow bugs in the SystemLoadDefaultDxe driver. The SystemLoadDefaultDxe driver is used in various Lenovo product lines, including Yoga, IdeaPad, Flex, ThinkBook, V14, V15, V130, Slim, S145, S540, and S940, and impacts approximately seventy (70) individual models. According to ESET researchers, an attacker could leverage the bugs to hijack the operating system execution flow and disable security features. UEFI firmware attacks are extremely dangerous as threat actors are able to run malware early in an operating system’s boot process, which is prior to Windows’ built-in security protections being activated. When threat actors have this level of access, the potential to bypass or disable OS-level security protections, evade detection, and persist even after a disk is formatted are present. To address these security risks, users of the affected devices are recommended to download the latest available driver version for their specific products found on Lenovo’s official software download portal.