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Fencer Vulns
medium 6.5

CVE-2020-15563 json

An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash.

published 2020-07-07 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-7550

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits
0
none known

Summary

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.

Patch / fix

  • xen Debian 14, Debian 13, Debian 12 4.11.4+24-gddaaccbbab-1

debian advisories DEBIAN-CVE-2020-15563

  • xen Ubuntu 20.04 LTS 4.11.3+24-g14b62ab3e5-1ubuntu2.3

ubuntu advisories UBUNTU-CVE-2020-15563

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • xen SLE Module for Server Applications 15 SP2, SLE Module for Basesystem 15 SP2 4.13.1_04-3.4.1
  • xen SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 4.11.4_04-2.30.1
  • xen SLE Module for Server Applications 15 SP1, SLE Module for Basesystem 15 SP1 4.12.3_04-3.22.1
  • xen SLES for SAP 15, SLE High Performance Computing 15-LTSS, SLE High Performance Computing 15-ESPOS 4.10.4_12-3.35.1
  • xen SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 4.12.3_04-3.18.1
  • xen SLES for SAP 12 SP3, SLES 12 SP3-LTSS, SLES 12 SP3-BCL +4 more 4.9.4_08-3.66.1

suse advisories SUSE-SU-2020:1902-1SUSE-SU-2020:1891-1SUSE-SU-2020:1889-1SUSE-SU-2020:1888-1SUSE-SU-2020:1887-1SUSE-SU-2020:1886-1

  • xen openSUSE Tumbleweed 4.15.1_01-1.2
  • xen openSUSE Leap 15.2 4.13.1_04-lp152.2.3.1
  • xen openSUSE Leap 15.1 4.12.3_04-lp151.2.21.1

opensuse advisories openSUSE-SU-2024:11520-1openSUSE-SU-2020:0985-1openSUSE-SU-2020:0965-1

  • xen Alpine 3.10 4.12.3-r2
  • xen Alpine 3.12, Alpine 3.11 4.13.1-r2
  • xen Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 4.13.1-r4
  • xen Alpine 3.9 4.11.4-r0

alpine advisories ALPINE-CVE-2020-15563

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-15563 updated cvss 5.6

xen: inverted code paths in x86 dirty VRAM tracking leads to DoS (XSA-319)

  • Red Hat Enterprise Linux 5 kernel-xen
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
NVD 2.0 4.7 AV:L/AC:M/Au:N/C:N/I:N/A:C

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.