Vulnerability identifier: #VU31971

Vulnerability risk: Medium

CVSSv3.1: 5.9 [CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-11742

CWE-ID: CWE-252

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Xen
Server applications / Virtualization software

Vendor: Xen Project

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to introduction of unexpected behavior in the fix for CVE-2017-1213 that caused bad continuation handling in GNTTABOP_copy. A remote user can crash the hypervisor.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Xen: 4.0.0 - 4.13.0

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External links
http://lists.opensuse.org/opensuse-security-announce/2020-05/msg00006.html
http://www.openwall.com/lists/oss-security/2020/04/14/4
http://xenbits.xen.org/xsa/advisory-318.html
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5M2XRNCHOGGTJQBZQJ7DCV6ZNAKN3LE2/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NVTP4OYHCTRU3ONFJOFJQVNDFB25KLLG/
http://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YMAW7D2MP6RE4BFI5BZWOBBWGY3VSOFN/
http://security.gentoo.org/glsa/202005-08
http://www.debian.org/security/2020/dsa-4723
http://xenbits.xen.org/xsa/advisory-318.html

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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