CVE-2020-27675

Name: CVE-2020-27675
Creator: NVD / NIST
Published: 2020-10-22T21:15:14.153+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 4.7/10EPSS 0.27%

Last modified Jun 17, 2026

CVE-2020-27675 is a medium-severity vulnerability rated 4.7/10 on the CVSS scale. An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). EPSS estimates a 0.27% chance of exploitation in the next 30 days.

Description

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device, aka CID-073d0552ead5.

Metrics

CVSS 3.1

4.7/10

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

EPSS Probability

0.27%

17.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	<= 5.9.1
Fedoraproject	Fedora	31
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Debian	Debian Linux	9.0

References

http://www.openwall.com/lists/oss-security/2021/01/19/3Mailing List, Third Party Advisory
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=073d0552ead5bfc7a3a9c01de590e924f11b5dd2Patch, Vendor Advisory
https://github.com/torvalds/linux/commit/073d0552ead5bfc7a3a9c01de590e924f11b5dd2Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/12/msg00015.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/12/msg00027.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3ZG6TZLD23QO3PV2AN2HB625ZX47ALTT/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6USZ4APZSBQDHGJLJMHW5JBN4QZV6SKZ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNF2R7FUT4IOJ2RIRGQ7X5R4F4FVVLSR/
https://security.gentoo.org/glsa/202011-06Third Party Advisory
https://xenbits.xen.org/xsa/advisory-331.htmlPatch, Vendor Advisory
http://www.openwall.com/lists/oss-security/2021/01/19/3Mailing List, Third Party Advisory
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=073d0552ead5bfc7a3a9c01de590e924f11b5dd2Patch, Vendor Advisory
https://github.com/torvalds/linux/commit/073d0552ead5bfc7a3a9c01de590e924f11b5dd2Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/12/msg00015.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/12/msg00027.htmlMailing List, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/3ZG6TZLD23QO3PV2AN2HB625ZX47ALTT/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6USZ4APZSBQDHGJLJMHW5JBN4QZV6SKZ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GNF2R7FUT4IOJ2RIRGQ7X5R4F4FVVLSR/
https://security.gentoo.org/glsa/202011-06Third Party Advisory
https://xenbits.xen.org/xsa/advisory-331.htmlPatch, Vendor Advisory

Timeline

Published: Oct 22, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-27675?

How severe is CVE-2020-27675?

CVE-2020-27675 has a CVSS score of 4.7/10 (MEDIUM severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27675?

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.

Are you affected by CVE-2020-27675?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST