Joplin is a free, open source note taking and to-do application. A Cross site scripting (XSS) vulnerability in affected versions allows clicking on an untrusted image link to execute arbitrary shell commands. The HTML sanitizer (`packages/renderer/htmlUtils.ts::sanitizeHtml`) preserves `<map>` `<area>` links. However, unlike `<a>` links, the `target` and `href` attributes are not removed. Additionally, because the note preview pane isn't sandboxed to prevent top navigation, links with `target` set to `_top` can replace the toplevel electron page. Because any toplevel electron page, with Joplin's setup, has access to `require` and can require node libraries, a malicious replacement toplevel page can import `child_process` and execute arbitrary shell commands. This issue has been fixed in co