sudo cp -rp /home/my_home /media/backup/my_home

From cp manpage:

 -p     same as --preserve=mode,ownership,timestamps

 --preserve[=ATTR_LIST]
          preserve the specified attributes (default: mode,ownership,timestamps),
          if possible additional attributes: context, links, xattr, all

Security in WordPress is taken very seriously, but as with any other system there are potential security issues that may arise if some basic security precautions aren't taken. This article will introduce you to basic security concepts and serve as an introductory guide to making your WordPress website more secure.

This article is not the ultimate quick fix to your security concerns.

You can use this script to fix wordpress permission:

#!/bin/bash
#
# This script configures WordPress file permissions based on recommendations
# from http://codex.wordpress.org/Hardening_WordPress#File_permissions
#
# Author: Michael Conigliaro <mike [at] conigliaro [dot] org>
#
WP_OWNER=www-data # <-- wordpress owner
WP_GROUP=www-data # <-- wordpress group
WP_ROOT=$1 # <-- wordpress root directory
WS_GROUP=www-data # <-- webserver group

# reset to safe defaults
find ${WP_ROOT} -exec chown ${WP_OWNER}:${WP_GROUP} {} \;
find ${WP_ROOT} -type d -exec chmod 755 {} \;
find ${WP_ROOT} -type f -exec chmod 644 {} \;

# allow wordpress to manage wp-config.php (but prevent world access)
chgrp ${WS_GROUP} ${WP_ROOT}/wp-config.php
chmod 660 ${WP_ROOT}/wp-config.php

# allow wordpress to manage wp-content
find ${WP_ROOT}/wp-content -exec chgrp ${WS_GROUP} {} \;
find ${WP_ROOT}/wp-content -type d -exec chmod 775 {} \;
find ${WP_ROOT}/wp-content -type f -exec chmod 664 {} \;

save it to a file and run it and pass it your wp installation directory:

wget https://gist.github.com/Adirael/3383404/raw/6c5446d56477426faeb709e5b807f00422acdea2/fix-wordpress-permissions.sh
chmod +x fix-wordpress-permissions.sh
sudo ./fix-wordpress-permissions.sh /var/www/html

https://gist.github.com/Adirael/3383404