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Fencer Vulns
medium 5.5

CVE-2020-11743 json

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP…

published 2020-04-14 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-4085

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 44%
public exploits
0
none known

Summary

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.

Patch / fix

  • xen Debian 14, Debian 13, Debian 12 4.11.4-1

debian advisories DEBIAN-CVE-2020-11743

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

ubuntu advisories UBUNTU-CVE-2020-11743

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 SLES for SAP 15, SLE High Performance Computing 15-LTSS, SLE High Performance Computing 15-ESPOS 4.10.4_10-3.31.1
  • xen SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 4.12.2_04-3.11.1
  • xen SLES for SAP 12 SP4, SLES 12 SP4, SLE Software Development Kit 12 SP4 4.11.3_04-2.23.1
  • xen SLE Module for Server Applications 15 SP1, SLE Module for Basesystem 15 SP1 4.12.2_04-3.15.1

suse advisories SUSE-SU-2020:1634-1SUSE-SU-2020:1139-1SUSE-SU-2020:1138-1SUSE-SU-2020:1124-1

  • xen openSUSE Tumbleweed 4.15.1_01-1.2
  • xen openSUSE Leap 15.1 4.12.2_04-lp151.2.15.1

opensuse advisories openSUSE-SU-2024:11520-1openSUSE-SU-2020:0599-1

  • xen Alpine 3.10 4.12.2-r1
  • xen Alpine 3.11 4.13.0-r1
  • xen Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 4.13.0-r3
  • xen Alpine 3.8 4.10.4-r3
  • xen Alpine 3.9 4.11.3-r2

alpine advisories ALPINE-CVE-2020-11743

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-2020-11743 updated cvss 5.9

xen: bad error path in GNTTABOP_map_grant (XSA-316)

  • 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

0.53% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • xenbits.xen.org https://xenbits.xen.org/xsa/advisory-316.html referenced PoC, tagged "exploit" by a source, unverified
  • xenbits.xen.org http://xenbits.xen.org/xsa/advisory-316.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness
  • CWE-755 Improper Handling of Exceptional Conditions

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.