Install libapache2-mpm-itk by entering the following commands in the terminal:
sudo apt update sudo apt install libapache2-mpm-itk
Description:
multiuser module for Apache
The mpm-itk module, although not technically a Multi-Processing Module (MPM) (although it used to be) enhances the classical "prefork" module (that is, without threads), in such a way that it allows you to constrain each individual vhost to a particular system user and group. This allows you to run several different web sites on a single server without worrying that they will be able to read each others' files. mpm-itk is largely independent of e.g. what scripting technology is in use on your server; in particular, it does not require you to run your scripts as CGI to get the extra security benefit.
Homepage: http://mpm-itk.sesse.net/
Version: 2.4.7-04-1
Section: universe/libs