GNU LibreDWG Dwggrep Utility dwggrep.c match_BLOCK_HEADER null pointer dereference

A security flaw has been discovered in GNU LibreDWG up to 0.14. The affected element is the function match_BLOCK_HEADER of the file dwggrep.c of the component Dwggrep Utility. Performing a manipulation results in null pointer dereference. The attack requires a local approach. The exploit has been released to the public and may be used for attacks.