CVE-2019-19580: An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable pro...

Description

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations, because of an incomplete fix for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations. Despite extensive testing and auditing, some corner cases were missed. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All security-supported versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Note that these attacks require very precise timing, which may be difficult to exploit in practice.

Metrics

CVSS 3.1

6.6/10

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.19%

63.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-362

Affected Software

Vendor	Product	Versions
Xen	Xen	<= 4.12.1
Fedoraproject	Fedora	31

References

Timeline

Published: Dec 11, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-19580?

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations, because of an incomplete fix for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations. Despite extensive testing and auditing, some corner cases were missed. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All security-supported versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Note that these attacks require very precise timing, which may be difficult to exploit in practice.

How severe is CVE-2019-19580?

CVE-2019-19580 has a CVSS score of 6.6/10 (MEDIUM severity). The EPSS model estimates a 1.19% probability of exploitation in the next 30 days.

How do I fix CVE-2019-19580?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.