Vulnerability identifier: #VU29601

Vulnerability risk: Medium

CVSSv3.1: 5.2 [CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2020-15563

CWE-ID: CWE-822

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 inverted code paths in x86 dirty VRAM tracking in Xen. An attacker with access to HVM guest operating system can crash the hypervisor.

Note: the vulnerability affects x86 systems only.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Xen: 4.8.0 - 4.13.1

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External links
http://www.openwall.com/lists/oss-security/2020/07/07/3
http://xenbits.xen.org/xsa/advisory-319.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. However, proof of concept for this vulnerability is available.