A remote code execution vulnerability exists in Microsoft SharePoint where APIs aren't properly protected from unsafe data input. An attacker who successfully exploited the vulnerability could run arbitrary code in the context of the SharePoint application pool and the SharePoint server farm account. Exploitation of this vulnerability requires that a user access a susceptible API on an affected version of SharePoint with specially-formatted input. The security update addresses the vulnerability by correcting how SharePoint handles deserialization of untrusted data.