Epiceditor – Cross-Site Scripting

EpicEditor Introduction

EpicEditor is an embeddable JavaScript Markdown editor with split fullscreen editing, live previewing, automatic draft saving, offline support, and more. For developers, it offers a robust API, can be easily themed, and allows you to swap out the bundled Markdown parser with anything you throw at it.

The project url:https://github.com/OscarGodson/EpicEditor

Causes of Vulnerability

EpicEditor uses marked.js(https://github.com/chjj/marked) to render the page, but does not filter the input tags, resulting in an XSS vulnerability.

TEST version

EpicEditor-0.2.2

Vulnerability reproduction

Create new test.html, reference edipeditor.js

 And then visit test.html, in the editor, <img src = 0 onerror = alert (1)>, click on the preview, the results as shown below

Bug fixes

marked.defaults = {
 gfm: true,
 tables: true,
 breaks: false,
 pedantic: false,
 sanitize: false,
 silent: false,
 highlight: null
};

Set sanitize to true, or call marked.setOptions ({sanitize: true}) in the previous render;