Zettlr version 2.3.0 allows an external attacker to remotely obtain arbitrary local files on any client that attempts to view a malicious markdown file through Zettlr. This is possible because the application does not have a CSP policy (or at least not strict enough) and/or does not properly validate the contents of markdown files before rendering them.

Zettlr version 2.3.0 allows an external attacker to remotely obtain arbitrary local files on any client that attempts to view a malicious markdown file through Zettlr. This is possible because the application does not have a CSP policy (or at least not strict enough) and/or does not properly validate the contents of markdown files before rendering them.