CVE-2020-1243: 
vulnerability analysis and mitigation

A denial of service vulnerability (CVE-2020-1243) was identified in Microsoft Hyper-V, affecting host servers that fail to properly validate specific malicious data from guest operating system users. The vulnerability was initially recorded on November 4, 2019, and is known as 'Windows Hyper-V Denial of Service Vulnerability'. This security issue specifically impacts Microsoft Hyper-V installations on host servers (CVE Mitre, NVD).

The vulnerability has been assessed with a CVSS v3.1 Base Score of 7.8 (HIGH) with the following vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Under CVSS v2.0, it received a Base Score of 4.6 (MEDIUM) with the vector (AV:L/AC:L/Au:N/C:P/I:P/A:P). The technical nature of the vulnerability relates to improper validation of specific data from guest operating systems (NVD).

The vulnerability can result in a denial of service condition on affected Microsoft Hyper-V host servers. When successfully exploited, this vulnerability could allow an attacker to cause the host server to fail in handling specific requests, potentially impacting the availability of the virtualization services (NVD).

Microsoft has released a security update that addresses the vulnerability by resolving the conditions where Hyper-V would fail to handle malicious requests. The fix specifically targets the validation process of data received from guest operating systems (NVD).