Cross-site Scripting (XSS) - Reflected in craigk5n/webcalendar
Oct 1st 2021
Cross-Site Scripting (XSS) attacks are a type of injection, in which malicious scripts are injected into websites. An attacker can use XSS to send a malicious script to an unsuspecting user. The end user’s browser has no way to know that the script should not be trusted, and will execute the script.
https://github.com/craigk5n/webcalendar/ is vulnerable to XSS as shown below:
Proof of Concept
$eType = getgetvalue ('eType');
<form action="edit_entry_handler.php" method="post" name="editentryform" ' . 'id="editentryform"> <input type="hidden" name="eType" value="' . $eType . '" />'
Login to webcalendar In a browser visit the following URL:
Because it thinks the script came from a trusted source, the malicious script can access any cookies, session tokens, or other sensitive information retained by the browser and used with that site. These scripts can even rewrite the content of the HTML page.
Hey hitisec, I've emailed the maintainers for you.
Working on fix, Should be ready in a week or so in next release.
Fix is in bootstrap-ui branch and will be included in next release.
Thanks for the heads up!
The fix for this is now included in the WebCalendar v1.9.0 release.