CVE-2021-28713 Denial of service in Linux
A malicious driver domain can cause denial of service in guest VMs by sending high-frequency console events, requiring patched Xen hypervisors.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-28713?
CVE-2021-28713 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 5 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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
Which versions are affected by CVE-2021-28713?
It affects 2 products.
Products include Debian Debian Linux, Xen Xen.
How do I fix CVE-2021-28713?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-28713 being exploited?
There is no known exploitation of CVE-2021-28713 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2021-28713, GHSA-5qm6-7cgc-v552, UBUNTU-CVE-2021-28713.