Vulnerability identifier: #VU49941

Vulnerability risk: Low

CVSSv3.1: 6.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-27672

CWE-ID: CWE-362

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description

The vulnerability allows a local authenticated user to execute arbitrary code.

An issue was discovered in Xen through 4.14.x allowing x86 guest OS users to cause a host OS denial of service, achieve data corruption, or possibly gain privileges by exploiting a race condition that leads to a use-after-free involving 2MiB and 1GiB superpages.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Xen: 4.0.0 - 4.14.1

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External links
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/2021/01/19/7
http://xenbits.xen.org/xsa/advisory-345.html
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XIK57QJOVOPWH6RFRNMGOBCROBCKMDG2/
http://security.gentoo.org/glsa/202011-06
http://www.debian.org/security/2020/dsa-4804
http://xenbits.xen.org/xsa/advisory-345.html

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.