LinuxBabu ………..

The private key contains a series of numbers. Two of those numbers form the “public key”, the others are part of your “private key”. The “public key” bits are also embedded in your Certificate (we get them from your CSR). To check that the public key in your cert matches the public portion of your private key, you need to view the cert and the key and compare the numbers. To view the Certificate and the key run the commands:

$ openssl x509 -noout -text -in server.crt
$ openssl rsa -noout -text -in server.key

The `modulus’ and the `public exponent’ portions in the key and the Certificate must match. But since the public exponent is usually 65537 and it’s bothering comparing long modulus you can use the following approach:

$ openssl x509 -noout -modulus -in server.crt | openssl md5
$ openssl rsa -noout -modulus -in server.key | openssl md5

And then compare these really shorter numbers. With overwhelming probability they will differ if the keys are different. As a “one-liner”:

$ openssl x509 -noout -modulus -in server.pem | openssl md5 ;\
openssl rsa -noout -modulus -in server.key | openssl md5

And with auto-magic comparison (If more than one hash is displayed, they don’t match):

$ (openssl x509 -noout -modulus -in server.pem | openssl md5 ;\
openssl rsa -noout -modulus -in server.key | openssl md5) | uniq

BTW, if I want to check to which key or certificate a particular CSR belongs you can compute

$ openssl req -noout -modulus -in server.csr | openssl md5

A potential security issue has been discovered whereby it may be possible for a malicious user to inject a specially crafted combination of variables leading to unexpected results. The issue revolves around the Smarty templating system and template related processing.

> Patch Download Link: http://www.whmcs.com/go/21/download

Patch will work for all versions of WHMCS 4.x.

Buy WHMCS cheap at Licensepal.com

For apache 1.3, edit your /etc/httpd/conf/httpd.conf and add

ExtendedStatus On
<Location /httpd-status>
SetHandler server-status
Order deny,allow
Deny from all
Allow from 127.0.0.1
</Location>

 

 

 

just after the code that says “ServerSignature On”. Save, exit, then restart apache. You can access the stats page by going to http://1.2.3.4/httpd-status where 1.2.3.4 is your server’s IP.

If you’re running apache 2.x , then it’s already in the file:
/etc/httpd/conf/extra/httpd.conf
Change the “Allow from” lines to include your IP.

Under cPanel servers the code is already present but you need to uncomment it or just add the code :

<Location /whm-server-status>
SetHandler server-status
Order deny,allow
Deny from all
Allow from 127.0.0.1
</Location>

2. After getting the license confirmation, SSH to the cPanel server as root, download the installer using the command below:

3. Open WHM as root user, at the bottom left menu under Plugins section, you can find RVSiteBuilder Installer menu.

4. Click RVSiteBuilder Installer to begin the installation process.

5. After complete the installation, you will be sent to RVSiteBuilder Manager automatically.

Click on the “Show/Edit Reserved IPs” link under “IP Functions”. Check the box of the ip you want to reserve and add a short comment to the Reason section. This ip will no longer be used to setup accounts via WHM/Cpanel.

There are two ways to update your Apache version on cpanel.

The first is from within WHM. Underneath the “Software” section in the menubar is “Apache Update.” Click this link and then follow the on screen directions.

The second option is from the command line. Run “/scripts/easyapache”, which will provide an update interface including a few more options than WHM.

It is highly recommended that you create a backup of your Apache configuration before preforming an update to a newer version.

Change the IP exim uses to send mail – bypass sorbs (or other useless blacklists)

On shared hosting server’s you’ll probably find yourself blocked by other mail providers because of high mail volume or one of your users spamming. To change your exim IP for outgoing mail, you can edit your /etc/exim.conf file and locate this section:

remote_smtp:
driver = smtp

And below this add:

interface – xxx.xxx.xxx.xxx

Replace the x’s with the backup mail IP. Note that the backup mail IP needs to be added to the server, and should have a valid PTR and A-record.

Note:  On newer versions of cPanel where domainkeys are installed, you will need to add another interface line:

dk_remote_smtp:
driver = smtp
dk_private_key = “/var/cpanel/domain_keys/private/${dk_domain}”
dk_canon = nofws
dk_selector = default
interface = xxx.xxx.xxx.xxx

Now restart exim.

Note: If there is an exim update when you upgrade your cpanel server you will need to re-enter the interface again.

Running a WHM like Cpanel can sure make hosting easy, but unfortunately running a WHM often makes your server much less secure than it was before!

We do not guaranty that the following steps will make your server hack proof, but it will greatly reduce your chances of compromise. Also note that Layered Technologies does not manage your server and if you do not feel comfortable making system level changes to your server we recommend you open a level2 support ticket (for a fee) or hire a third party sysadmin service to help you.

Basic Steps to Securing CPanel (Linux based OS):

These are items inside of WHM/Cpanel that should be changed to secure your server.

Goto Server Setup =>> Tweak Settings

Check the following items…

Under Domains
Prevent users from parking/adding on common internet domains. (ie hotmail.com, aol.com)

Under Mail
Attempt to prevent pop3 connection floods
Default catch-all/default address behavior for new accounts – blackhole

Under System
Use jailshell as the default shell for all new accounts and modified accounts

Goto Server Setup =>> Tweak Security
Enable php open_basedir Protection
Enable mod_userdir Protection
Disabled Compilers for unprivileged users.

Goto Server Setup =>> Manage Wheel Group Users
Remove all users except for root and your main account from the wheel group.

Goto Server Setup =>> Shell Fork Bomb Protection
Enable Shell Fork Bomb/Memory Protection

When setting up Feature Limits for resellers in Resellers =>> Reseller Center, under Privileges always disable Allow Creation of Packages with Shell Access and enable Never allow creation of accounts with shell access; under Root Access disable All Features.

Goto Service Configuration =>> FTP Configuration
Disable Anonymous FTP

Goto Account Functions =>> Manage Shell Access
Disable Shell Access for all users (except yourself)

Goto Mysql =>> MySQL Root Password
Change root password for MySQL

Goto Security and run Quick Security Scan and Scan for Trojan Horses often. The following and similar items are not Trojans:
/sbin/depmod
/sbin/insmod
/sbin/insmod.static
/sbin/modinfo
/sbin/modprobe
/sbin/rmmod

These are measures that can be taken to secure your server, with SSH access.

Udate OS, Apache and CPanel to the latest stable versions.

This can be done from WHM/CPanel.

Restrict SSH Access

To restrict and secure SSH access, bind sshd to a single IP that is different than the main IP to the server, and on a different port than port 22.

SSH into server and login as root.

Note: You can download Putty by Clicking Here. It’s a clean running application that will not require installation on Windows-boxes.

At command prompt type: pico /etc/ssh/sshd_config

Scroll down to the section of the file that looks like this:
Code:

#Port 22
#Protocol 2, 1
#ListenAddress 0.0.0.0
#ListenAddress ::

Uncomment and change

#Port 22

to look like

Port 5678 (choose your own 4 to 5 digit port number (49151 is the highest port number)

Uncomment and change

#Protocol 2, 1

to look like

Protocol 2

Uncomment and change

#ListenAddress 0.0.0.0

to look like

ListenAddress 123.123.123.15 (use one of your own IP Addresses that has been assigned to your server)

Note 1: If you would like to disable direct Root Login, scroll down until you find

#PermitRootLogin yes

and uncomment it and make it look like

PermitRootLogin no

Save by pressing Ctrl o on your keyboard, and then exit by pressing Ctrl x on your keyboard.

Now restart SSH

At command prompt type: /etc/rc.d/init.d/sshd restart

Exit out of SSH, and then re-login to SSH using the new IP or nameserver, and the new port.

Disable Telnet

To disable telnet, SSH into server and login as root.

At command prompt type: pico -w /etc/xinetd.d/telnet

change disable = no to disable = yes

Save and Exit

At command prompt type: /etc/init.d/xinetd restart

Server e-mail everytime someone logs in as root

To have the server e-mail you everytime someone logs in as root, SSH into server and login as root.

At command prompt type: pico .bash_profile

Scroll down to the end of the file and add the following line:

echo ‘ALERT – Root Shell Access on:’ `date` `who` | mail -s “Alert: Root Access from `who | awk ‘{print $6}’`” your@email.com

Save and exit.

Set an SSH Legal Message

To an SSH legal message, SSH into server and login as root.

At command prompt type: pico /etc/motd

Enter your message, save and exit.

Note: I use the following message…
Code:

ALERT! You are entering a secured area! Your IP and login information
have been recorded. System administration has been notified.

This system is restricted to authorized access only. All activities on
this system are recorded and logged. Unauthorized access will be fully
investigated and reported to the appropriate law enforcement agencies.

Now everytime someone logs in, they will see this message… go ahead a try it.

Disable Shell Accounts

To disable any shell accounts hosted on your server SSH into server and login as root.

At command prompt type: locate shell.php

Also check for:

locate irc
locate eggdrop
locate bnc
locate BNC
locate ptlink
locate BitchX
locate guardservices
locate psyBNC
locate .rhosts

Note: There will be several listings that will be OS/CPanel related. Examples are

/home/cpapachebuild/buildapache/php-4.3.1/ext/ircg
/usr/local/cpanel/etc/sym/eggdrop.sym
/usr/local/cpanel/etc/sym/bnc.sym
/usr/local/cpanel/etc/sym/psyBNC.sym
/usr/local/cpanel/etc/sym/ptlink.sym
/usr/lib/libncurses.so
/usr/lib/libncurses.a
etc.

Disable identification output for Apache

To disable the version output for proftp, SSH into server and login as root.

At command prompt type: pico /etc/httpd/conf/httpd.conf

Scroll (way) down and change the following line to

ServerSignature Off

Restart Apache

At command prompt type: /etc/rc.d/init.d/httpd restart

These are applications that will help to secure your server.

Install chkrootkit

To install chrootkit, SSH into server and login as root.

At command prompt type: cd /root/

At command prompt type: wget ftp://ftp.pangeia.com.br/pub/seg/pac/chkrootkit.tar.gz

At command prompt type: tar xvzf chkrootkit.tar.gz

At command prompt type: cd chkrootkit-0.44

At command prompt type: make sense

To run chkrootkit

At command prompt type: /root/chkrootkit-0.44/chkrootkit

Make sure you run it on a regular basis, perhaps including it in a cron job.

I have seen recent cPanel upgrade throwing errors are below :

root@server [~]# /scripts/upcp
/scripts/upcp syntax OK
Running Futex Check/Fix……Done
Undefined subroutine &Cpanel::Update::automatic_updates_enabled called at /scripts/upcp line 273.

This can be fixed using below :

wget -O /root/updatenow.static http://httpupdate.cpanel.net/cpanelsync/RELEASE/scripts/updatenow.static && perl /root/updatenow.static --manual

Upgrade the cPanel :

/scripts/upcp --force

This should fix the issue

MySQL dies and logs shows error as below :

[ERROR] /usr/sbin/mysqld: Table './eximstats/sends' is marked as crashed and last (automatic?) repair failed
[ERROR] /usr/sbin/mysqld: Table './eximstats/sends' is marked as crashed and last (automatic?) repair failed

A simple fix is to repair the tables using command :

myisamchk -r /var/lib/mysql/eximstats/sends.MYI
- recovering (with sort) MyISAM-table '/var/lib/mysql/eximstats/sends.MYI'
Data records: 1292
- Fixing index 1
- Fixing index 2
- Fixing index 3
Data records: 3265

All should be good.