void PDFiumEngine::Form_DisplayCaret(FPDF_FORMFILLINFO* param,
                                     FPDF_PAGE page,
                                     FPDF_BOOL visible,
                                     double left,
                                     double top,
                                     double right,
                                     double bottom) {}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.