Title

If the Trivial File Transfer Protocol (TFTP) server is required, the TOSS TFTP daemon must be configured to operate in secure mode. (Cat II impact)

Discussion

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

Check Content

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

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

Additional Identifiers

Rule ID: SV-253102r991589_rule

Vulnerability ID: V-253102

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

CCIs tied to check.

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