CVE-2020-11743

Published: 14 April 2020

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.

Priority

Medium

CVSS 3 base score: 5.5

Status

Notes

hypervisor packages are in universe. For
issues in the hypervisor, add appropriate
tags to each section, ex:
Tags_xen: universe-binary

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11743
• https://xenbits.xen.org/xsa/advisory-316.html
• http://www.openwall.com/lists/oss-security/2020/04/14/3
• http://xenbits.xen.org/xsa/advisory-316.html
• NVD
• Launchpad
• Debian