CVE-2020-17090: 
vulnerability analysis and mitigation

Microsoft Defender for Endpoint Security Feature Bypass Vulnerability (CVE-2020-17090) was disclosed on November 11, 2020. This vulnerability affects various versions of Microsoft Windows 10 (1803, 1809, 1903, 1909, 2004) and Windows Server 2016/2019 systems (NVD CVE).

The vulnerability has received varying severity assessments. According to the National Vulnerability Database, it was assigned a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. However, Microsoft's own assessment rated it as MEDIUM severity with a CVSS score of 5.3 and vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N. Under CVSS v2.0, it received a HIGH severity rating with a base score of 7.5 (NVD CVE).

The vulnerability could allow an attacker to bypass security features in Microsoft Defender for Endpoint, potentially compromising the system's security protections. The high CVSS scores indicate potential for complete compromise of confidentiality, integrity, and availability of the affected systems (NVD CVE).

Microsoft has released security patches to address this vulnerability. The fix is available through the standard Windows Update mechanism for affected systems including Windows 10 versions 1803 through 2004, and Windows Server 2016/2019 (NVD CVE).