CVE-2021-28711

Rogue backends can cause DoS of guests via high frequency events T[his CNA
information record relates to multiple CVEs; the text explains which
aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to
run PV backends in regular unprivileged guests, typically referred to as
“driver domains”. Running PV backends in driver domains has one primary
security advantage: if a driver domain gets compromised, it doesn’t have
the privileges to take over the system. However, a malicious driver domain
could try to attack other guests via sending events at a high frequency
leading to a Denial of Service in the guest due to trying to service
interrupts for elongated amounts of time. There are three affected
backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2,
CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713

Notes