What is CVE-2019-18422?

CVE-2019-18422 is a high-severity vulnerability in Xen, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 8.8/10. Published 2019-10-31.

How severe is CVE-2019-18422?

High severity. CVSS v3 base score is 8.8 out of 10.

Vulnerability in Xen

CVE-2019-18422

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.

Published 2019-10-31 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.018 (77.9th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 78th percentile — 77.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.018 · newest: 0.018 · change: 0.000

Affected products

Xen
Debian Linux — versions 9.0, 10.0
Fedoraproject Fedora — versions 29, 30, 31

Weakness classification (CWE)

CWE-732 — Incorrect Permission Assignment for Critical Resource

References

xenbits.xen.org/xsa/advisory-303.html (Patch, Vendor Advisory)
www.openwall.com/lists/oss-security/2019/10/31/5 (mailing-list, Patch, Mailing List, Third Party Advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
www.debian.org/security/2020/dsa-4602 (vendor-advisory, Third Party Advisory)
seclists.org/bugtraq/2020/Jan/21 (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2019-18422?: CVE-2019-18422 is a high-severity vulnerability in Xen, classified under Incorrect Permission Assignment for Critical Resource. CVSS score: 8.8/10. Published 2019-10-31.
How severe is CVE-2019-18422?: High severity. CVSS v3 base score is 8.8 out of 10.