|Description||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|
|Source||CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)|
|References||DLA-2940-1, DLA-2941-1, DSA-5050-1, DSA-5096-1, ELA-577-1|
Vulnerable and fixed packages
The table below lists information on source packages.
|linux (PTS)||jessie, jessie (lts)||3.16.84-1||vulnerable|
|stretch (lts), stretch||4.9.320-3||fixed|
|linux-4.19 (PTS)||stretch (security)||4.19.232-1~deb9u1||fixed|
|stretch (lts), stretch||4.19.289-2~deb9u1||fixed|
|linux-4.9 (PTS)||jessie, jessie (lts)||4.9.303-1~deb8u3||fixed|
The information below is based on the following data on fixed versions.