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3.1.2 Ensure wireless interfaces are disabled

Audit#

Run the following script to verify no wireless interfaces are active on the system: 

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#!/usr/bin/env bash
{
l_output="" l_output2=""
module_chk()
{
# Check how module will be loaded
l_loadable="$(modprobe -n -v "$l_mname")"
if grep -Pq -- '^\h*install \/bin\/(true|false)' <<< "$l_loadable";
then
l_output="$l_output\n - module: \"$l_mname\" is not loadable: \"$l_loadable\""
else
l_output2="$l_output2\n - module: \"$l_mname\" is loadable: \"$l_loadable\""
fi
# Check is the module currently loaded
if ! lsmod | grep "$l_mname" > /dev/null 2>&1; then
l_output="$l_output\n - module: \"$l_mname\" is not loaded"
else
l_output2="$l_output2\n - module: \"$l_mname\" is loaded"
fi
# Check if the module is deny listed
if modprobe --showconfig | grep -Pq -- "^\h*blacklist\h+$l_mname\b";
then
l_output="$l_output\n - module: \"$l_mname\" is deny listed in: \"$(grep -Pl -- "^\h*blacklist\h+$l_mname\b" /etc/modprobe.d/*)\""
else
l_output2="$l_output2\n - module: \"$l_mname\" is not deny listed"
fi
}
if [ -n "$(find /sys/class/net/*/ -type d -name wireless)" ]; then
l_dname=$(for driverdir in $(find /sys/class/net/*/ -type d -name wireless | xargs -0 dirname); do basename "$(readlink -f "$driverdir"/device/driver/module)";done | sort -u)
for l_mname in $l_dname; do
module_chk
done
fi
# Report results. If no failures output in l_output2, we pass
if [ -z "$l_output2" ]; then
echo -e "\n- Audit Result:\n ** PASS **"
if [ -z "$l_output" ]; then
echo -e "\n - System has no wireless NICs installed"
else
echo -e "\n$l_output\n"
fi
else
echo -e "\n- Audit Result:\n ** FAIL **\n - Reason(s) for audit failure:\n$l_output2\n"
[ -n "$l_output" ] && echo -e "\n- Correctly set:\n$l_output\n"
fi
}

Remediation#

Run the following script to disable any wireless interfaces: 

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#!/usr/bin/env bash
{
module_fix()
{
if ! modprobe -n -v "$l_mname" | grep -P -- '^\h*install \/bin\/(true|false)'; then
echo -e " - setting module: \"$l_mname\" to be un-loadable"
echo -e "install $l_mname /bin/false" >> /etc/modprobe.d/"$l_mname".conf
fi
if lsmod | grep "$l_mname" > /dev/null 2>&1; then
echo -e " - unloading module \"$l_mname\""
modprobe -r "$l_mname"
fi
if ! grep -Pq -- "^\h*blacklist\h+$l_mname\b" /etc/modprobe.d/*; then
echo -e " - deny listing \"$l_mname\""
echo -e "blacklist $l_mname" >> /etc/modprobe.d/"$l_mname".conf
fi
}
if [ -n "$(find /sys/class/net/*/ -type d -name wireless)" ]; then
l_dname=$(for driverdir in $(find /sys/class/net/*/ -type d -name wireless | xargs -0 dirname); do basename "$(readlink -f "$driverdir"/device/driver/module)";done | sort -u)
for l_mname in $l_dname; do
module_fix
done
fi
}