Intel TXT SINIT Authenticated Code Module for some Intel processors: Improper initialization in the SINIT ACM

Impact

Improper initialization in the SINIT ACM - the Intel-signed module that performs the TXT measured launch. A privileged local attacker can escalate through it, which means the dynamic root of trust that a TXT launch is supposed to establish can be subverted at the moment it is created. If you use TXT (directly, or via a launch control policy that gates whether a node may join a secure pool), an attacker can make a compromised node produce a passing launch. Nodes admitted to a trusted pool on that basis are not trustworthy, and the compromise is at firmware level so it crosses tenant handoff.

Who can reach it

A privileged local user on the node - local root or SMM-capable code.

What to do

New SINIT ACM delivered inside a BIOS/platform-firmware update from the OEM (Dell, HPE, Supermicro, Lenovo, Gigabyte, Quanta), plus updating any standalone SINIT binary your tboot/launch stack loads. Host reboot and job drain. If you gate scheduling on TXT launch results, update the launch control policy hashes at the same time or the policy will fail closed and strand capacity.

References