The TFTP daemon must operate in secure mode which provides access only to a single directory on the host file system.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-38701	RHEL-06-000338	SV-50502r2_rule		High

Description
Using the "-s" option causes the TFTP service to only serve files from the given directory. Serving files from an intentionally specified directory reduces the risk of sharing files which should remain private.

STIG	Date
Red Hat Enterprise Linux 6 Security Technical Implementation Guide	2018-11-28

Details

Check Text ( C-46263r2_chk )
Verify the "tftp" package is installed: # rpm -qa \| grep -i tftp tftp-5.2-22.e16.x86_64 If the "tftp" package is not installed, this is Not Applicable. Verify "tftp" is configured by with the "-s" option by running the following command: grep "server_args" /etc/xinetd.d/tftp The output should indicate the "server_args" variable is configured with the "-s" flag, matching the example below: # grep "server_args" /etc/xinetd.d/tftp server_args = -s /var/lib/tftpboot If it does not, this is a finding.

Check Text ( C-46263r2_chk )

Verify the "tftp" package is installed:
# rpm -qa | grep -i tftp
tftp-5.2-22.e16.x86_64

If the "tftp" package is not installed, this is Not Applicable.

Verify "tftp" is configured by with the "-s" option by running the following command:

grep "server_args" /etc/xinetd.d/tftp

The output should indicate the "server_args" variable is configured with the "-s" flag, matching the example below:

# grep "server_args" /etc/xinetd.d/tftp
server_args = -s /var/lib/tftpboot

If it does not, this is a finding.

Fix Text (F-43650r1_fix)
If running the "tftp" service is necessary, it should be configured to change its root directory at startup. To do so, ensure "/etc/xinetd.d/tftp" includes "-s" as a command line argument, as shown in the following example (which is also the default): server_args = -s /var/lib/tftpboot