CVE-2020-15563 Null dereference in n/a
A malicious x86 HVM guest can crash the Xen hypervisor via a null pointer dereference in video RAM tracking, causing host-wide denial of service.
- 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-2020-15563?
CVE-2020-15563 is a medium-severity vulnerability in Debian Debian Linux, published on 7 Jul 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 x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HVM guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Xen versions from 4.8 onwards are affected. Xen versions 4.7 and earlier are not affected. Only x86 systems are affected. Arm systems are not affected. Only x86 HVM guests using shadow paging can leverage the vulnerability. In addition, there needs to be an entity actively monitoring a guest's video frame buffer (typically for display purposes) in order for such a guest to be able to leverage the vulnerability. x86 PV guests, as well as x86 HVM guests using hardware assisted paging (HAP), cannot leverage the vulnerability.
Weakness: CWE-119
Which versions are affected by CVE-2020-15563?
It affects 4 products.
Products include Debian Debian Linux, Fedoraproject Fedora, Opensuse Leap, Xen Xen.
How do I fix CVE-2020-15563?
Apply the vendor's patch.
Is CVE-2020-15563 being exploited?
There is no known exploitation of CVE-2020-15563 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as ALPINE-CVE-2020-15563, DEBIAN-CVE-2020-15563, GHSA-wwfw-7rgm-hmmc, UBUNTU-CVE-2020-15563.