SV-253102r1134939: If the Trivial File Transfer Protocol (TFTP) server is required, the TOSS TFTP daemon must be configured to operate in secure mode. | Tri-Lab Operating System Stack (TOSS) 4 STIG SCAP Benchmark

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Assessment Title

Rule Text

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

Description

Discussion Text

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

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-000366

References

DPMS Target TOSS 4 DISA DPMS Target TOSS 4 5469

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

#!/bin/bash
# Reconstructed from oval:mil.disa.stig.toss4os:def:253102
# If the Trivial File Transfer Protocol (TFTP) server is required, the TOSS TFTP daemon must be configured to operate in secure mode.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# The tftp-server package is absent.
# rpminfo_object (rpminfo_test)
test_1() {
  ! ( rpm -q --quiet 'tftp-server' &>/dev/null )
}
# /etc/xinetd.d/tftp: server_args has a -s option with a subdirectory assigned
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  grep -Pq '^server_args[ \t]*=[ \t]*-s[ \t]+/\S+[ \t]*$' '/etc/xinetd.d/tftp' &>/dev/null
}

if ( test_1 || test_2 ); then
  echo "PASS"
else
  echo "FAIL"
fi

Assessment Script Powered by AISandbox-executed

A standalone Shell script to assess this control automatically. Review before running it in your environment.

Syntax-checked and actually executed in an isolated sandbox (not the real system this checks) — confirmed to run without errors.

#!/bin/sh
# OVAL Definition: oval:mil.disa.stig.toss4os:def:253102
if ! rpm -q tftp-server >/dev/null 2>&1; then
    echo "PASS"
    exit 0
fi
if ! grep -q "^server_args[ \t]*=[ \t]*-s[ \t]*/\\S*[ \t]*$" /etc/xinetd.d/tftp; then
    echo "FAIL"
    exit 1
fi
echo "PASS"
exit 0

Remediation

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