Just tested #zenbleed between two KVM/QEMU VMs. It worked.. 🤨​

Scenario:
OS running two Ubuntu 22.04 live systems. VMs share a CPU core from the host. Victim VM is running curl against localhost nginx with "Bearer" auth header. Attacker VM only runs zenbleed PoC.

Zenbleed PoC captures the client's header string FROM THE OTHER VM. 💣​

The VMs ONLY share a host hardware CPU core, nothing else.

From my POV this shows that it is possible to capture client credentials from other VMs on the same host, given some time.

What the f?

#amd #zenbleed #security #kvm #qemu