CVE-2020-15563

MEDIUMCVSS 6.5/10EPSS 0.41%

Last modified

CVE-2020-15563 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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. EPSS estimates a 0.41% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
6.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

EPSS Probability
0.41%

33.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
XenXen>= 4.8.0, <= 4.13.1
DebianDebian Linux10.0
FedoraprojectFedora31
FedoraprojectFedora32
OpensuseLeap15.2

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-15563?
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.
How severe is CVE-2020-15563?
CVE-2020-15563 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.41% probability of exploitation in the next 30 days.
How do I fix CVE-2020-15563?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-15563?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST