This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Aurelia Framework
The HTMLSanitizer class in html-sanitizer.ts in all released versions of the Aurelia framework 1.x repository is vulnerable to XSS. The sanitizer only attempts to filter SCRIPT elements, which makes it feasible for remote attackers to conduct XSS attacks via (for example) JavaScript code in an attribute of various other elements. An attacker might also exploit a bug in how the SCRIPT string is processed by splitting and nesting them for example. (2021-05-13, CVE-2019-10062)
Why Cross-site Scripting can be dangerous
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>