When the parseAuditHeaderFromJSON() function performs a AuditHeaderOptionsDocument::parse() of the input audit header BSON object fileHeaderBSON, it stores an un-owned BSONObj for the _keyStoreIdentifier member variable. This causes a use-after-free when the owning BSON object goes out of scope at function return, and the resulting AuditHeaderOptionsDocument object's _keyStoreIdentifier is used later in createKeyManagerFromHeader().