This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Connection Broker
** UNSUPPORTED WHEN ASSIGNED ** LeoStream Connection Broker 9.x before 9.0.34.3 allows Unauthenticated Reflected XSS via the /index.pl user parameter. NOTE: This vulnerability only affects products that are no longer supported by the maintainer. (2021-08-06, CVE-2021-38157)
** UNSUPPORTED WHEN ASSIGNED ** Leostream Connection Broker 8.2.x is affected by stored XSS. An unauthenticated attacker can inject arbitrary JavaScript code via the webquery.pl User-Agent HTTP header. It is rendered by the admins the next time they log in. The JavaScript injected can be used to force the admin to upload a malicious Perl script that will be executed as root via libMisc::browser_client. NOTE: This vulnerability only affects products that are no longer supported by the maintainer. (2020-10-06, CVE-2020-26574)
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>