CVE-2021-31966: 
vulnerability analysis and mitigation

CVE-2021-31966 is a remote code execution vulnerability affecting Microsoft SharePoint Server. The vulnerability was disclosed and addressed by Microsoft in their June 8, 2021 security updates (Microsoft Support). The affected systems include SharePoint Server 2013 SP1 and SharePoint Enterprise Server 2016.

This vulnerability is classified as a remote code execution vulnerability in Microsoft SharePoint Server. The specific technical details of the exploitation method have not been publicly disclosed by Microsoft. The vulnerability requires the release version of Service Pack 1 for Microsoft SharePoint Server 2013 or Microsoft SharePoint Enterprise Server 2016 to be installed on the affected system (Microsoft Support).

The vulnerability could allow an attacker to execute arbitrary code on affected SharePoint Server installations. As a remote code execution vulnerability, successful exploitation could potentially give attackers significant control over the affected systems (CVE Mitre).

Microsoft has released security updates to address this vulnerability. The fixes are available through multiple channels: Microsoft Update, Microsoft Update Catalog, and as standalone packages through the Microsoft Download Center. For SharePoint Server 2013, users need to install security update KB5001954, while SharePoint Server 2016 users should install security update KB5001946 (Microsoft Support).