Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. This vulnerability is caused by adding note titles to the document using React's `dangerouslySetInnerHTML`, without first escaping HTML entities. Joplin lacks a Content-Security-Policy with a restrictive `script-src`. This allows arbitrary JavaScript execution via inline `onclick`/`onload` event handlers in unsanitized HTML. Additionally, Joplin's main window is created with `nodeIntegration` set to `true`, allowing arbitrary JavaScript execution to result in arbitrary code execution. Anyone who 1) receives notes from unknown sources and 2) uses <kbd>ctrl</kbd>-<kbd>p</kbd> to search is impacted. This issue has been addressed in version 3.1.24 and all users are advised to upgrade. There are no known workarounds for this vulnerability.
