Interscan Web Security Virtual Appliance Cross-site Scripting

Trend Micro InterScan Web Security Virtual Appliance version 6.5 was found to have a reflected cross-site scripting (XSS) vulnerability in the product's Captive Portal. (2021-06-17, CVE-2021-31521)

A cross-site scripting (XSS) vulnerability in Trend Micro InterScan Web Security Virtual Appliance 6.5 SP2 could allow an attacker to tamper with the web interface of the product in a manner separate from the similar CVE-2020-8462. (2020-12-17, CVE-2020-27010)

A cross-site scripting (XSS) vulnerability in Trend Micro InterScan Web Security Virtual Appliance 6.5 SP2 could allow an attacker to tamper with the web interface of the product. (2020-12-17, CVE-2020-8462)

A cross-site scripting vulnerability (XSS) in Trend Micro InterScan Web Security Virtual Appliance 6.5 may allow a remote attacker to tamper with the web interface of affected installations. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. (2020-05-27, CVE-2020-8603)

Cross site scripting is an attack where a web page executes code that is injected by an adversary. It usually appears, when users input is presented. This attack can be used to impersonate a user, take over control of the session, or even steal API keys.

The attack can be executed e.g. when you application injects the request parameter directly into the HTML code of the page returned to the user:

https://server.com/confirmation?message=Transaction+Complete

what results in:

<span>Confirmation: Transaction Complete</span>

In that case the message can be modified to become a valid Javascript code, e.g.:

https://server.com/confirmation?message=<script>dangerous javascript code here</script>

and it will be executed locally by the user's browser with full access to the user's personal application/browser data:

<span>Confirmation: <script>dangerous javascript code here</script></span>