CVE-2020-11742 Denial of service in n/a
A malicious guest OS can cause a denial of service in the Xen hypervisor by triggering incorrect grant table copy 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-2020-11742?
CVE-2020-11742 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 bad continuation handling in GNTTABOP_copy. Grant table operations are expected to return 0 for success, and a negative number for errors. The fix for CVE-2017-12135 introduced a path through grant copy handling where success may be returned to the caller without any action taken. In particular, the status fields of individual operations are left uninitialised, and may result in errant behaviour in the caller of GNTTABOP_copy. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to copy a grant, it hits the incorrect exit path. This returns success to the caller without doing anything, which may cause crashes or other incorrect behaviour.
Which versions are affected by CVE-2020-11742?
It affects 2 products.
Products include Fedoraproject Fedora, Xen Xen.
How do I fix CVE-2020-11742?
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-2020-11742 being exploited?
There is no known exploitation of CVE-2020-11742 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as ALPINE-CVE-2020-11742, DEBIAN-CVE-2020-11742, GHSA-q23v-6m98-94w9, UBUNTU-CVE-2020-11742.