Some Lenovo System x server BIOS/UEFI versions, when Secure Boot mode is enabled by a system administrator, do not properly authenticate signed code before booting it. As a result, an attacker with physical access to the system could boot unsigned code.

An unprivileged attacker with connectivity to the IMM2 could cause a denial of service attack on the IMM2 (Versions earlier than 4.4 for Lenovo System x and earlier than 6.4 for IBM System x). Flooding the IMM2 with a high volume of authentication failures via the Common Information Model (CIM) used by LXCA and OneCLI and other tools can exhaust available system memory which can cause the IMM2 to reboot itself until the requests cease.

The BIOS in Lenovo System X M5, M6, and X6 systems allows administrators to cause a denial of service via updating a UEFI data structure.