Mapnik dbfile.cpp string_value heap-based overflow

A security vulnerability has been detected in Mapnik up to 4.2.0. This issue affects the function mapnik::dbf_file::string_value of the file plugins/input/shape/dbfile.cpp. Such manipulation leads to heap-based buffer overflow. The attack must be carried out locally. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.