If the Trivial File Transfer Protocol (TFTP) server is required, the RHEL 8 TFTP daemon must be configured to operate in secure mode.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-230557	RHEL-08-040350	SV-230557r599732_rule		Medium

Description
Restricting TFTP to a specific directory prevents remote users from copying, transferring, or overwriting system files.

STIG	Date
Red Hat Enterprise Linux 8 Security Technical Implementation Guide	2020-11-25

Details

Check Text ( C-33226r568417_chk )
Verify the TFTP daemon is configured to operate in secure mode with the following commands: $ sudo yum list installed tftp-server tftp-server.x86_64 x.x-x.el8 If a TFTP server is not installed, this is Not Applicable. If a TFTP server is installed, check for the server arguments with the following command: $ sudo grep server_args /etc/xinetd.d/tftp server_args = -s /var/lib/tftpboot If the "server_args" line does not have a "-s" option, and a subdirectory is not assigned, this is a finding.

Check Text ( C-33226r568417_chk )

Verify the TFTP daemon is configured to operate in secure mode with the following commands:

$ sudo yum list installed tftp-server

tftp-server.x86_64 x.x-x.el8

If a TFTP server is not installed, this is Not Applicable.

If a TFTP server is installed, check for the server arguments with the following command:

$ sudo grep server_args /etc/xinetd.d/tftp

server_args = -s /var/lib/tftpboot

If the "server_args" line does not have a "-s" option, and a subdirectory is not assigned, this is a finding.

Fix Text (F-33201r568418_fix)
Configure the TFTP daemon to operate in secure mode by adding the following line to "/etc/xinetd.d/tftp" (or modify the line to have the required value): server_args = -s /var/lib/tftpboot