This article is a part of our Vulnerability Database (back to index)
Cross-site Scripting occurrences in Davical
A reflected XSS issue was discovered in DAViCal through 1.1.8. It echoes the action parameter without encoding. If a user visits an attacker-supplied link, the attacker can view all data the attacked user can view, as well as perform all actions in the name of the user. If the user is an administrator, the attacker can for example add a new admin user to gain full access to the application. (2019-12-12, CVE-2019-18345)
A stored XSS issue was discovered in DAViCal through 1.1.8. It does not adequately sanitize output of various fields that can be set by unprivileged users, making it possible for JavaScript stored in those fields to be executed by another (possibly privileged) user. Affected database fields include Username, Display Name, and Email. (2019-12-04, CVE-2019-18347)
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>