important · Boot chain / Physical
A $159 DDR5 interposer can expose Intel TDX guest plaintext and forge attestation.
Affects
Intel TDX, hardware-isolated confidential virtual machines on Xeon cloud servers.
With the interposer installed and the host or hypervisor under attacker control, suppressed DDR5 writes leave prepared stale ciphertext that TDX accepts.
Detail and 4 sources
Researchers used the primitive to change a trust domain's debug state, access plaintext and replace a launch measurement; the hardware designs and attack code are public.