Title

If the Trivial File Transfer Protocol (TFTP) server is required, the RHEL 8 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

Note: IAW RHEL-08-040190 if TFTP is not required, it should not be installed. If TFTP is not installed, this rule is not applicable. Check to see if TFTP server is installed with the following command: $ sudo dnf list installed | grep tftp-server tftp-server.x86_64 x.x-x.el8 Verify that the TFTP daemon, if tftp.server is installed, is configured to operate in secure mode with the following command: $ grep -i execstart /usr/lib/systemd/system/tftp.service ExecStart=/usr/sbin/in.tftpd -s /var/lib/tftpboot Note: The "-s" option ensures that the TFTP server only serves files from the specified directory, which is a security measure to prevent unauthorized access to other parts of the file system. If the TFTP server is installed but the TFTP daemon is not configured to operate in secure mode, this is a finding.

Fix Text

Configure the TFTP daemon to operate in secure mode with the following command: $ sudo systemctl edit tftp.service In the editor enter: [Service] ExecStart=/usr/sbin/in.tftpd -s /var/lib/tftpboot After making changes, reload the systemd daemon and restart the TFTP service as follows: $ sudo systemctl daemon-reload $ sudo systemctl restart tftp.service

Additional Identifiers

Rule ID: SV-230557r1088855_rule

Vulnerability ID: V-230557

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

Expert Comments

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