Typora 0.9.9.24.6 on macOS allows directory traversal, for execution of arbitrary programs, via a file:/// or ../ substring in a shared note.
https://twitter.com/RandomDhiraj/status/1136960564540915712
https://github.com/typora/typora-issues/issues/2505
http://packetstormsecurity.com/files/153082/Typora-0.9.9.24.6-Directory-Traversal.html