Update operator injection via single-element list rewriting in the update builder

A data-query-logic neutralization weakness in the update-statement construction component of the MongoDB C# Driver can cause application-supplied values to be interpreted as query/update logic rather than as literal data. An application user who can influence the content of values that the application passes into the affected builder surface, without any special privilege beyond ordinary read-write application access, may cause stored data to be modified or removed in ways the application never intended. The result is unauthorized integrity impact on the affected application data; there is no direct loss of confidentiality or availability of the database service.