Posts Tagged ‘Read Write’

Change website .JS .PHP Python Perl CSS etc. file permissions recursively for Better Tightened Security on Linux Webhosting Servers

Friday, October 30th, 2015

change-permissions-recursively-on-linux-to-protect-website-against-security-breaches-hacks

It is a common security (breach) mistake that developers or a web design studio make with dedicated or shared hosted websites do to forget to set a nice restrictive file permissions.

This is so because most people (and especially nowdays) developers are not a security freaks and the important think for a programmer is to make the result running in shortest time without much caring on how secure that is.
Permissions issues are common among sites written in PHP / Perl / Python with some CSS and Javascript, but my observations are that JavaScript websites especially that are using some frameworks such as Zend / Smarty etc. and are using JQuery are the most susceptible to suffer from permission security holes such as the classic 777 file permissions, because of developers who’re overworking and pushed up for a deadlines to include new functionality on websites and thus often publish their experimental code on a Production systems without a serious testing by directly uploading the experimental code via FTP / WinSCP on Production system.

Such scenarios are very common for small and middle sized companies websites as well as many of the hobbyist developers websites running on ready CMS system platforms such as Joomla and WordPress.
I know pretty well from experience this is so. Often a lot of the servers where websites are hosted are just share-servers without a dedicated sysadmin and thus there are no routine security audits made on the server and the security permissions issue might lead to a serious website compromise by a cracker and make your website quickly be banned from Google / Yahoo / Ask Jeeves / Yandex and virtually most of Search Engines because of being marked as a spammer or hacked webiste inside some of the multiple website blacklists available nowdays.

Thus it is always a good idea to keep your server files (especially if you’re sysadmin) with restrictive permissions by making the files be owned by superuser (root) in order to prevent some XSS or vulnerable PHP / Python / Perl script to allow you to easily (inject) and overwrite code on your website.

1. Checking whether you have a all users read, write, executable permissions with find command

The first thing to do on your server to assure you don’t have a low security permissioend files is:

find /home/user/website -type f -perm 777 -print

You will get some file as an output like:

./www/tpl/images/js/ajax-dynamic-list/js/ajax-dynamic-list.js
./www/tpl/images/js/ajax-dynamic-list/js/ajax_admin.js
./www/tpl/images/js/ajax-dynamic-list/js/ajax_teams.js
./www/tpl/images/js/ajax-dynamic-list/js/ajax.js
./www/tpl/images/js/ajax-dynamic-list/js/ajax-dynamic-list_admin.js
./www/tpl/images/js/ajax-dynamic-list/lgpl.txt

2. Change permissions recursively to read, write and exec for root and read for everybody and set all files to be owned by (root) superuser

Then to fix the messy permissions files a common recommended permissions is 744 (e.g. Read / Write and Execute permissions for everyone and only read permissions for All Users and All groups).
Lets say you want to make files permissions to 744 just for all JavaScript (JQuery) files for a website, here is how:

find . -iname ‘*.js’ -type f -print -exec chown root:root ‘{}’ \;
find . -iname ‘*.js’ -type f -print -exec chmod 744 ‘{}’ \;

First find makes all Javascript files be owned by root user / group and second one sets all files permissions to 744.

To make 744 all files on server (including JPEG / PNG Pictures) etc.:

find . -iname /home/users/website -type f -print -exec chown root:root ‘{}’ \;
find . -iname /home/users/website -type f -print -exec chmod 744 ‘{}’ \;

WordPress Security: Fix WordPress wp-config.php improper permissions to protect your sites from Database password steal / Website deface

Thursday, March 12th, 2015

wordpress-security-Fix-wordpress-wp-config-improper-permissions-to-protect-your-sites-from-Database-pass-steal
Keeping WordPress Site / Blog and related installed plugins up-to-date
is essential to prevent an attacker to hack into your Site / Database and deface your site, however if you're a company providing shell access from Cpanel / Plesk / Kloxo Panel to customers often customers are messing up permissions leaving important security credential files such as wp-config.php (which is storing user / pass credentials about connection to MySQL / PostgreSQL to have improper permissions and be world readable e.g. have permissions such as 666 or 777 while in reality the WordPress recommended permissions for wp-config.php is 600. I will skip here to explain in details difference between file permissions on Linux as this is already well described in any Linux book, however I just will recommend for any Share hosting Admin where Wordperss is hosted on Lighttpd / Apache Webserver + Some kind of backend database to be extra cautious.

Hence it is very useful to list all your WordPress sites on server wp-config.php permissions with find like this:

find /  -iname 'wp-config.php' -print1;

I find it a generally good practice to also automatically set all wp-config.php permissions to 600 (6= Read / Write  permissions only for File Owner  user 0 = No permissions for All groups, 0 = No Permissions for all non-owner users)

If find command output gives you some file permissions such as:
 

ls -al /var/www/wordpress-bak/wp-config.php
-rw-rw-rw- 1 www-data www-data 2654 jul 28  2009 wp-config.php

E.g. file permission has 666 permissions (Readable for all users), then it is wise to fix this with:
 

chmod 600 /var/www/wordpress-bak/wp-config.php


It is generally a very good practice to run also a chmod 600 to each and every found wp-config.php file on server:
 

find /  -iname 'wp-config.php' -print1 -exec chmod 600 '{}' \;


Above command will also print each file to whcih permission is set to Read / Write for Owner (this si done with -print1 option).

It is a good practice for shared hosting server to always configure a root cronjob to run above find chmod command at least once daily (whenever server hosts 50 – 100 wordpress+ more sites).
 

crontab -u root -l | { cat; echo “05 03 * * * find /  -iname 'wp-config.php' -print1 -exec chmod 600 '{}' \; } | crontab – 


If you don't have the 600 permissions set for all wp-config.php files this security "backdoor" can be used by any existing non-root user to be read and to break up (crack)  in your database and even when there are Deface bot-nets involved to deface all your hosted server wordpress sites.

One of my servers with wordpress has just recently suffered with this little but very important security hole due to a WordPress site directory backup  with improper permissions which allowed anyone to enter MySQL database, so I guess there are plenty of servers with this hidden vulnerability silently living.

Many thanks to my dear friend (Dimitar PaskalevNomen for sharing with me about this vulnerability! Very important note to make here is admins who are using some security enhancement modules such as SuPHP (which makes Apache webserver to run Separate Website instances with different user), should be careful with his set all wp-config.php modules to Owner, as it is possible the wp-config.php owner change to make customer WP based websites inaccessible.

Another good security measure to  protect your server WordPress based sites from malicious theme template injections (for both personal own hosted wordpress based blog / sites or a WordPress hosting company) is to install and activate WordPress Antivirus plugin.