RHEL 9 must disable the graphical user interface automount function unless required.

STIG ID: RHEL-09-271020  |  SRG: SRG-OS-000114-GPOS-00059 | Severity: medium |  CCI: CCI-000366,CCI-000778,CCI-001958

Vulnerability Discussion

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

Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227

Check

Verify RHEL 9 disables the graphical user interface automount function with the following command:

Note: This requirement assumes the use of the RHEL 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.

$ gsettings get org.gnome.desktop.media-handling automount-open

false

If "automount-open" is set to "true", and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

Fix

Configure the GNOME desktop to disable automated mounting of removable media.

The dconf settings can be edited in the /etc/dconf/db/* location.

Update the [org/gnome/desktop/media-handling] section of the "/etc/dconf/db/local.d/00-security-settings" database file and add or update the following lines:

[org/gnome/desktop/media-handling]
automount-open=false

Then update the dconf system databases:

$ sudo dconf update