A zero-day exploit for Parallels Plesk up to and including revision 10.4.4 has been in circulation since yesterday and is already being exploited. A remote file inclusion enables attackers to read passwords, files and databases as well as to execute code. The takeover of the Plesk panel and all hosted sites is thus possible. By using the same passwords on other systems and services such as SSH, passwords that have already been read open the door to your server for attackers even months later.
We therefore strongly recommend updating to the latest Plesk Panel 11.0.9, the latest revision is not affected by the exploit. In addition, you should also change the passwords of all Plesk users and all the same passwords of other systems and services.
Further information and notes can be found at:
If you have any questions about this notice or if you need help updating your Plesk panel, our support will of course be happy to help.