CVE-2019-18422

Published: 31 October 2019

An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service or gain privileges by leveraging the erroneous enabling of interrupts. Interrupts are unconditionally unmasked in exception handlers. When an exception occurs on an ARM system which is handled without changing processor level, some interrupts are unconditionally enabled during exception entry. So exceptions which occur when interrupts are masked will effectively unmask the interrupts. A malicious guest might contrive to arrange for critical Xen code to run with interrupts erroneously enabled. This could lead to data corruption, denial of service, or possibly even privilege escalation. However a precise attack technique has not been identified.

Priority

Medium

CVSS 3 base score: 8.8

Status

Package Release Status
xen
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 21.10 (Impish Indri) Not vulnerable
(4.11.3+24-g14b62ab3e5-1ubuntu1)
Ubuntu 21.04 (Hirsute Hippo) Not vulnerable
(4.11.3+24-g14b62ab3e5-1ubuntu1)
Ubuntu 20.04 LTS (Focal Fossa) Not vulnerable
(4.11.3+24-g14b62ab3e5-1ubuntu1)
Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 ESM (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Binaries built from this source package are in Universe and so are supported by the community.

Notes

AuthorNote
mdeslaur
hypervisor packages are in universe
amurray
This issue is specific only to ARM platforms - x86 systems are not affected

References