Making global modifications to users' files without alerting the user community can result in unexpected outages and unhappy users. Therefore, it is recommended that a monitoring policy be established to report user dot file permissions and determine the action to be taken in accordance with site policy. The following script will: - remove excessive permissions on dot files within interactive users' home directories - change ownership of dot files within interactive users' home directories to the user - change group ownership of dot files within interactive users' home directories to the user's primary group - list .forward and .rhost files to be investigated and manually deleted #!/usr/bin/env bash { l_valid_shells="^($( awk -F\/ '$NF != "nologin" {print}' /etc/shells | sed -rn '/^\//{s,/,\\\\/,g;p}' | paste -s -d '|' - ))$" unset a_uarr && a_uarr=() # Clear and initialize array while read -r l_epu l_eph; do # Populate array with users and user home location [[ -n "$l_epu" && -n "$l_eph" ]] && a_uarr+=("$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_maxsize="1000" # Maximum number of local interactive users before warning (Default 1,000) [ "$l_asize " -gt "$l_maxsize" ] && echo -e "\n ** INFO **\n - \"$l_asize\" Local interactive users found on the system\n - This may be a long running check\n" file_access_fix() { l_facout2="" l_max="$( printf '%o' $(( 0777 & ~$l_mask)) )" if [ $(( $l_mode & $l_mask )) -gt 0 ]; then echo -e " - File: \"$l_hdfile\" is mode: \"$l_mode\" and should be mode: \"$l_max\" or more restrictive\n - Changing to mode \"$l_max\"" chmod "$l_chp" "$l_hdfile" fi if [[ ! "$l_owner" =~ ($l_user) ]]; then echo -e " - File: \"$l_hdfile\" owned by: \"$l_owner\" and should be owned by \"${l_user//|/ or }\"\n - Changing ownership to \"$l_user\"" chown "$l_user" "$l_hdfile" fi if [[ ! "$l_gowner" =~ ($l_group) ]]; then echo -e " - File: \"$l_hdfile\" group owned by: \"$l_gowner\" and should be group owned by \"${l_group//|/ or }\"\n - Changing group ownership to \"$l_group\"" chgrp "$l_group" "$l_hdfile" fi } while read -r l_user l_home; do if [ -d "$l_home" ]; then echo -e "\n - Checking user: \"$l_user\" home directory: \"$l_home\"" l_group="$(id -gn "$l_user" | xargs)" l_group="${l_group// /|}" while IFS= read -r -d $'\0' l_hdfile; do while read -r l_mode l_owner l_gowner; do case "$(basename "$l_hdfile")" in .forward | .rhost ) echo -e " - File: \"$l_hdfile\" exists\n - Please investigate and manually delete \"$l_hdfile\"" ;; .netrc ) l_mask='0177' l_chp="u-x,go-rwx" file_access_fix ;; .bash_history ) l_mask='0177' l_chp="u-x,go-rwx" file_access_fix ;; * ) l_mask='0133' l_chp="u-x,go-wx" file_access_fix ;; esac done <<< "$(stat -Lc '%#a %U %G' "$l_hdfile")" done < <(find "$l_home" -xdev -type f -name '.*' -print0) fi done <<< "$(printf '%s\n' "${a_uarr[@]}")" unset a_uarr # Remove array }

Name	Audit Name	Plugin	Category
6.2.10 Ensure local interactive user dot files access is configured	CIS Ubuntu Linux 18.04 LTS v2.2.0 L1 Server	Unix	ACCESS CONTROL, CONFIGURATION MANAGEMENT, IDENTIFICATION AND AUTHENTICATION, MEDIA PROTECTION
6.2.10 Ensure local interactive user dot files access is configured	CIS Ubuntu Linux 18.04 LTS v2.2.0 L1 Workstation	Unix	ACCESS CONTROL, CONFIGURATION MANAGEMENT, IDENTIFICATION AND AUTHENTICATION, MEDIA PROTECTION

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