Intel Ethernet 700 Series Controller firmware (access control): Insufficient access control inside 700-series NIC

Impact

Insufficient access control inside 700-series NIC firmware lets a privileged host user escalate further or deny service. On bare-metal GPU rental the 'privileged host user' is the tenant, and the thing they are escalating into is firmware that the next tenant will inherit. This is the concrete mechanism behind the tenant-handoff problem: patching the host OS between customers does nothing about the NIC.

Who can reach it

A privileged local user on the host — in a bare-metal rental model, the customer with root.

What to do

Flash 700-series firmware to 7.3 or later; cold power cycle. Operationally the stronger control is to reflash NIC firmware from a known-good image at every tenant handoff and verify the resulting version, rather than trusting whatever the previous tenant left behind. Related issues fixed in the same family: CVE-2020-8691, CVE-2020-8693, CVE-2019-0139, CVE-2019-0144.

References