Vulnerability Discussion

Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity.

Satisfies: SRG-OS-000378-GPOS-00163, SRG-OS-000114-GPOS-00059

Check

Note: This requirement assumes the use of the AlmaLinux OS 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable.

Verify AlmaLinux OS 9 disables ability of the user to override the graphical user interface automount setting.

Determine which profile the system database is using with the following command:

$ grep system-db /etc/dconf/profile/user

system-db:local

Check that the automount setting is locked from nonprivileged user modification with the following command:

Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used.

$ grep 'automount-open' /etc/dconf/db/local.d/locks/*

/org/gnome/desktop/media-handling/automount-open

If the command does not return at least the example result, this is a finding.

Fix

Configure the GNOME desktop to not allow a user to change the setting that disables automated mounting of removable media.

Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user modification:

/org/gnome/desktop/media-handling/automount-open

Then update the dconf system databases:

$ dconf update