Vulnerability identifier: #VU29602

Vulnerability risk: Low

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

CVE-ID: CVE-2020-15566

CWE-ID: CWE-399

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 improper error handling in event-channel port allocation in Xen. An attacker with access to guest operating system can consume more than 1023 event channels and crash the hypervisor.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Xen: 4.10.0 - 4.13.1

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External links
http://www.openwall.com/lists/oss-security/2020/07/07/2
http://xenbits.xen.org/xsa/advisory-317.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.