Input Feature Request: Easier Subdomain Isolation and Migration Between Subscriptions

[brother4]

With the increasing number of supply-chain attacks, particularly through compromised WordPress plugins and third-party dependencies, I believe Plesk should make it significantly easier to isolate websites and applications at the system-user level.

Currently, multiple domains and subdomains within the same subscription typically share the same Linux system user. This creates an unnecessary security risk: if one application is compromised, an attacker may potentially gain access to files and sensitive configuration data belonging to other applications.

While separate subscriptions provide better isolation, moving an existing subdomain into its own subscription is unnecessarily complicated. Plesk does not allow subdomains to be moved independently of their parent domain, requiring a manual migration process instead.

I would therefore suggest two improvements:

1. Per-domain and per-subdomain system users: Allow administrators to assign separate Linux system users to individual domains and subdomains, even when they belong to the same subscription.
2. Seamless migration between subscriptions: Provide a simple option to move an existing domain or subdomain into a separate subscription, automatically transferring its website files, databases, database users, PHP settings, scheduled tasks, and other relevant configurations while preserving the existing hostname.

Ideally, this should be possible directly from the Plesk interface, without having to create temporary domains, manually copy files and databases, or reconfigure everything afterward.

For administrators hosting multiple projects on the same server, this would be a major improvement in both security and everyday usability.

Especially with supply-chain attacks becoming an increasingly serious threat, stronger application isolation should be easy to implement rather than requiring a complicated migration process.

I would be interested to hear whether Plesk has considered such functionality or whether there are plans to improve domain-level isolation and subscription migration in the future.

Of course, Plesk already offers some security measures, such as restricting PHP file access through open_basedir:

• {WEBSPACEROOT}{/}subdomain.example.com{/}{:}{TMP}{/}
• {DOCROOT}{/}{:}{TMP}{/}

Additionally, potentially dangerous PHP functions can be disabled using disable_functions, for example:

opcache_get_status,exec,passthru,shell_exec,system,proc_open,popen,show_source,highlight_file,pcntl_exec

However, these are additional PHP-level restrictions rather than true operating system-level isolation. The main point of my suggestion is to make proper isolation between applications much easier and more accessible by default, without requiring administrators to manually configure and maintain numerous security restrictions or worry about potential bypasses. Ideally, Plesk should make it straightforward to run each domain or subdomain under its own system user, even within the same subscription.