CVE-2020-11743 Denial of service in n/a
A malicious guest OS can crash the Linux-based dom0 or backend domain by exploiting a logic error in Xen's grant table mapping error handling.
- 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-2020-11743?
CVE-2020-11743 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 14 Apr 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.
Weakness: CWE-755
Which versions are affected by CVE-2020-11743?
It affects 2 products.
Products include Fedoraproject Fedora, Xen Xen.
How do I fix CVE-2020-11743?
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-2020-11743 being exploited?
There is no known exploitation of CVE-2020-11743 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as ALPINE-CVE-2020-11743, DEBIAN-CVE-2020-11743, GHSA-ff8p-26v5-2cw5, UBUNTU-CVE-2020-11743.