CVE-2020-12625: Cross-Site Scripting via Malicious HTML Attachment in Roundcube Webmail

A Cross-Site scripting (XSS) vulnerability exists in Roundcube versions before 1.4.4, 1.3.11 and 1.2.10.

By leveraging the "<![CDATA[...]]>" XML element in a mail with a "text/html" attachment, an attacker can bypass the Roundcube script filter and execute arbitrary malicious JavaScript in the victim's browser when the malicious email is clicked.

Vendor Disclosure:

The vendor's disclosure and fix for this vulnerability can be found here.

Requirements:

This vulnerability requires:

• Waiting for a Roundcube user to open the email containg the XSS

Proof Of Concept:

More details and the exploitation process can be found in this PDF.