SV-258034r1051267: RHEL 9 must be configured to disable USB mass storage. | Red Hat Enterprise Linux 9 STIG SCAP Benchmark

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Assessment Title

Rule Text

RHEL 9 must be configured to disable USB mass storage.

Description

Discussion Text

USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227

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

IA Controls

NIST SP 800-53

Not mappedCCI-000778Not mappedCCI-001958Not mappedCCI-003959

References

DPMS Target Red Hat Enterprise Linux 9 DISA DPMS Target Red Hat Enterprise Linux 9 5551

Checks

DISA STIG (Manual Reference)

Verify that RHEL 9 disables the ability to load the USB Storage kernel module with the following command:

$ grep -r usb-storage /etc/modprobe.conf /etc/modprobe.d/* 

install usb-storage /bin/false
blacklist usb-storage

If the command does not return any output, or either line is commented out, and use of USB Storage is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

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.rhel9os:def:258034
# RHEL 9 must be configured to disable USB mass storage.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# /etc/modprobe.d contains a file that contains 'install usb-storage /bin/false'
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -rqP --include='*' '^[ \t]*install[ \t]+usb-storage[ \t]+/bin/false[ \t]*$' '/etc/modprobe.d' &>/dev/null
}
# /etc/modprobe.d contains a file that contains 'blacklist usb-storage'
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  grep -rqP --include='*' '^[ \t]*blacklist[ \t]+usb-storage[ \t]*$' '/etc/modprobe.d' &>/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.rhel9os:def:258034

if grep -q "^[ \\t]*install[ \\t]+usb-storage[ \\t]+/bin/false[ \\t]*$" /etc/modprobe.d/* && \
   grep -q "^[ \\t]*blacklist[ \\t]+usb-storage[ \\t]*$" /etc/modprobe.d/*; then
    echo "PASS"
    exit 0
else
    echo "FAIL"
    exit 1
fi

Remediation

To configure the system to prevent the usb-storage kernel module from being loaded, add the following lines to the file "/etc/modprobe.d/usb-storage.conf" (or create "usb-storage.conf" if it does not exist):

install usb-storage /bin/false
blacklist usb-storage