Remediation / Fixes :
Patched binaries for the affected versions have been released as Firecracker v0.18.1  and Firecracker v0.19.1 . If you are using Firecracker v0.18.0 or v0.19.0 , we recommend you apply the provided fix. If you are using Firecracker v0.17.0 or below, you do not need to take any action.
In a remote code execution scenario, users running Firecracker in line with the recommended Production Host Setup will see the impact limited as follows: a malicious microVM guest that would manage to compromise the Firecracker VMM process would be restricted to running on the host as an unprivileged user, in a chroot and mount namespace isolated from the host’s filesystem, in a separate pid namespace, in a separate network namespace, with system calls limited to Firecracker’s seccomp whitelist, on a single NUMA node, and on a cgroups-limited number of CPU cores.
 https://github.com/firecracker-microvm/firecracker/releases/tag/v0.18.1  https://github.com/firecracker-microvm/firecracker/releases/tag/v0.19.1