Vim: vimscript injection via unescaped filename in netrw s:netrwmarkfile() filter() expression allows arbitrary code execution

A flaw was found in Vim's netrw plugin. A crafted filename containing quote characters and expression fragments can break out of the quoted context during mark/unmark operations, allowing arbitrary Vimscript execution. This can be leveraged to run shell commands with the privileges of the user running Vim.