Title

RHEL 8 Bluetooth must be disabled. (Cat II impact)

Discussion

Without protection of communications with wireless peripherals, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read, altered, or used to compromise the RHEL 8 operating system. This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with RHEL 8 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR Keyboards, Mice, and Pointing Devices and Near Field Communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DoD requirements for wireless data transmission and be approved for use by the Authorizing Official (AO). Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the RHEL 8 operating system. Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of communications with wireless peripherals can be accomplished by physical means (e.g., employing physical barriers to wireless radio frequencies) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. If the wireless peripheral is only passing telemetry data, encryption of the data may not be required.

Check Content

If the device or operating system does not have a Bluetooth adapter installed, this requirement is not applicable. This requirement is not applicable to mobile devices (smartphones and tablets), where the use of Bluetooth is a local AO decision. Determine if Bluetooth is disabled with the following command: $ sudo grep bluetooth /etc/modprobe.d/* /etc/modprobe.d/bluetooth.conf:install bluetooth /bin/false If the Bluetooth driver blacklist entry is missing, a Bluetooth driver is determined to be in use, and the collaborative computing device has not been authorized for use, this is a finding. Verify the operating system disables the ability to use Bluetooth with the following command: $ sudo grep -r bluetooth /etc/modprobe.d | grep -i "blacklist" | grep -v "^#" blacklist bluetooth If the command does not return any output or the output is not "blacklist bluetooth", and use of Bluetooth is not documented with the ISSO as an operational requirement, this is a finding.

Fix Text

Configure the operating system to disable the Bluetooth adapter when not in use. Build or modify the "/etc/modprobe.d/bluetooth.conf" file with the following line: install bluetooth /bin/false Disable the ability to use the Bluetooth kernel module. $ sudo vi /etc/modprobe.d/blacklist.conf Add or update the line: blacklist bluetooth Reboot the system for the settings to take effect.

Additional Identifiers

Rule ID: SV-230507r1017287_rule

Vulnerability ID: V-230507

Group Title: SRG-OS-000300-GPOS-00118

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.