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7.2.9 Ensure local interactive user home directories are configured

Audit#

Run the following script to Ensure: - local interactive user home directories exist - Ensure local interactive users own their home directories - Ensure local interactive user home directories are mode 750 or more restrictive 

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#!/usr/bin/env bash
{
l_output="" l_output2="" l_heout2="" l_hoout2="" l_haout2=""
l_valid_shells="^($( awk -F\/ '$NF != "nologin" {print}' /etc/shells | sed -rn '/^\//{s,/,\\\\/,g;p}' | paste -s -d '|' - ))$"
unset a_uarr && a_uarr=() # Clear and initialize array
while read -r l_epu l_eph; do # Populate array with users and user home location
a_uarr+=("$l_epu $l_eph")
done <<< "$(awk -v pat="$l_valid_shells" -F: '$(NF) ~ pat { print $1 " "$(NF-1) }' /etc/passwd)"
l_asize="${#a_uarr[@]}" # Here if we want to look at number of users before proceeding
[ "$l_asize " -gt "10000" ] && echo -e "\n ** INFO **\n - \"$l_asize\"Local interactive users found on the system\n - This may be a long running check\n"
while read -r l_user l_home; do
if [ -d "$l_home" ]; then
l_mask='0027'
l_max="$( printf '%o' $(( 0777 & ~$l_mask)) )"
while read -r l_own l_mode; do
[ "$l_user" != "$l_own" ] && l_hoout2="$l_hoout2\n - User: \"$l_user\" Home \"$l_home\" is owned by: \"$l_own\""
if [ $(( $l_mode & $l_mask )) -gt 0 ]; then
l_haout2="$l_haout2\n - User: \"$l_user\" Home \"$l_home\" is mode: \"$l_mode\" should be mode: \"$l_max\" or more restrictive"
fi
done <<< "$(stat -Lc '%U %#a' "$l_home")"
else
l_heout2="$l_heout2\n - User: \"$l_user\" Home \"$l_home\" Doesn't exist"
fi
done <<< "$(printf '%s\n' "${a_uarr[@]}")"
[ -z "$l_heout2" ] && l_output="$l_output\n- home directories exist" || l_output2="$l_output2$l_heout2"
[ -z "$l_hoout2" ] && l_output="$l_output\n- own their home directory" || l_output2="$l_output2$l_hoout2"
[ -z "$l_haout2" ] && l_output="$l_output\n- home directories are mode:\"$l_max\" or more restrictive" || l_output2="$l_output2$l_haout2"
[ -n "$l_output" ] && l_output=" - All local interactive users:$l_output"
if [ -z "$l_output2" ]; then # If l_output2 is empty, we pass
echo -e "\n- Audit Result:\n ** PASS **\n - * Correctly configured * :\n$l_output"
else
echo -e "\n- Audit Result:\n ** FAIL **\n - * Reasons for audit failure * :\n$l_output2"
[ -n "$l_output" ] && echo -e "\n- * Correctly configured * :\n$l_output"
fi
}

Remediation#

If a local interactive users' home directory is undefined and/or doesn't exist, follow local site policy and perform one of the following: - Lock the user account - Remove the user from the system - create a directory for the user. If undefined, edit /etc/passwd and add the absolute path to the directory to the last field of the user.

Run the following script to: - Remove excessive permissions from local interactive users home directories - Update the home directory's owner

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#!/usr/bin/env bash
{
l_output2=""
l_valid_shells="^($( awk -F\/ '$NF != "nologin" {print}' /etc/shells | sed -rn '/^\//{s,/,\\\\/,g;p}' | paste -s -d '|' - ))$"
unset a_uarr && a_uarr=() # Clear and initialize array
while read -r l_epu l_eph; do # Populate array with users and user home location
a_uarr+=("$l_epu $l_eph")
done <<< "$(awk -v pat="$l_valid_shells" -F: '$(NF) ~ pat { print $1 " " $(NF-1) }' /etc/passwd)"
l_asize="${#a_uarr[@]}" # Here if we want to look at number of users before proceeding
[ "$l_asize " -gt "10000" ] && echo -e "\n ** INFO **\n - \"$l_asize\"Local interactive users found on the system\n - This may be a long running process\n"
while read -r l_user l_home; do
if [ -d "$l_home" ]; then
l_mask='0027'
l_max="$( printf '%o' $(( 0777 & ~$l_mask)) )"
while read -r l_own l_mode; do
if [ "$l_user" != "$l_own" ]; then
l_output2="$l_output2\n - User: \"$l_user\" Home \"$l_home\"is owned by: \"$l_own\"\n - changing ownership to: \"$l_user\"\n"
chown "$l_user" "$l_home"
fi
if [ $(( $l_mode & $l_mask )) -gt 0 ]; then
l_output2="$l_output2\n - User: \"$l_user\" Home \"$l_home\"is mode: \"$l_mode\" should be mode: \"$l_max\" or more restrictive\n - removing excess permissions\n"
chmod g-w,o-rwx "$l_home"
fi
done <<< "$(stat -Lc '%U %#a' "$l_home")"
else
l_output2="$l_output2\n - User: \"$l_user\" Home \"$l_home\"
Doesn't exist\n - Please create a home in accordance with local site policy"
fi
done <<< "$(printf '%s\n' "${a_uarr[@]}")"
if [ -z "$l_output2" ]; then # If l_output2 is empty, we pass
echo -e " - No modification needed to local interactive users home directories"
else
echo -e "\n$l_output2"
fi
}