What’s Vulnerable › Vulnerabilities

CVE-2020-27673

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-10-22 · updated 2026-06-17

Description

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. Guest OS users can cause a denial of service (host OS hang) via a high rate of events to dom0, aka CID-e99502f76271.

Affected products

• Debian Linux: 9.0
• Linux kernel: from 2.6.12 before 4.4.244; from 4.5.0 before 4.9.244; from 4.10.0 before 4.14.207; from 4.15.0 before 4.19.155; from 4.20.0 before 5.4.75; from 5.5.0 before 5.9.5 — fixed in 4.14.207, 4.19.155, 4.4.244, 4.9.244, 5.4.75, 5.9.5
• openSUSE Leap: 15.1, 15.2
• xen: through 4.14.0

How to fix

Upgrade to a fixed version: Linux kernel 4.14.207, 4.19.155, 4.4.244, 4.9.244. Check the vendor advisory for mitigations.

References

• http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00075.html
• http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00025.html
• http://www.openwall.com/lists/oss-security/2021/01/19/6
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e99502f76271d6bc4e374fe368c50c67a1fd3070
• https://github.com/torvalds/linux/commit/e99502f76271d6bc4e374fe368c50c67a1fd3070
• https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
• https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html
• https://security.gentoo.org/glsa/202011-06
• https://xenbits.xen.org/xsa/advisory-332.html
• http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00075.html
• http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00025.html
• http://www.openwall.com/lists/oss-security/2021/01/19/6

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