CVE-2018-19965 Denial of service in n/a
A 64-bit PV guest user can crash the host OS by triggering a general protection fault in TLB flushing code due to a flawed Meltdown mitigation.
- 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-2018-19965?
CVE-2018-19965 is a medium-severity denial of service vulnerability in Citrix Xenserver, published on 8 Dec 2018. 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 4.11.x allowing 64-bit PV guest OS users to cause a denial of service (host OS crash) because #GP[0] can occur after a non-canonical address is passed to the TLB flushing code. NOTE: this issue exists because of an incorrect CVE-2017-5754 (aka Meltdown) mitigation.
Which versions are affected by CVE-2018-19965?
It affects 3 products.
Products include Citrix Xenserver, Debian Debian Linux, Xen Xen.
How do I fix CVE-2018-19965?
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-2018-19965 being exploited?
There is no known exploitation of CVE-2018-19965 in the wild and no public exploit code.
Other vulnerabilities in Citrix Xenserver
Sources
Also known as ALPINE-CVE-2018-19965, DEBIAN-CVE-2018-19965, GHSA-c3g2-qp55-6gjf, UBUNTU-CVE-2018-19965.