Application Security London - Vulnerability Research


Compromising Plesk via its REST API

Plesk is a commercial web hosting and server data center automation software developed for Linux and Windows-based retail hosting service providers. It’s the main choice of web hosting providers these days being used by 86.7% of the websites that use a web panel for administration. This is 4.4% of all websites and there around 2M Plesk installations in the US alone. As expected there are many interesting features to attack as an administrator, however we couldn’t find anything really exploitable and also it isn’t that interesting to begin with, if you’re already an administrator, right? We tried to see if we can escalate our privileges from one of the limited roles, but these seem solid. In the end we discovered a cookieless CSRF, which is basically a design issue in this case, because it affects all the POST requests and we could abuse most of the APIs with it.

Multiple vulnerabilities in cPanel/WHM

cPanel is a web hosting control panel software developed by cPanel, LLC. It provides a graphical interface (GUI) and automation tools designed to simplify the process of hosting a web site to the website owner or the “end user”. It enables administration through a standard web browser using a three-tier structure. While cPanel is limited to managing a single hosting account, cPanel & WHM allows the administration of the entire server. Our team has found multiple vulnerabilities in cPanel/WHM during a black-box pentest, the most important ones being an RCE and privilege escalation via stored XSS.