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Version: 21.10

Secure your platform

This chapter suggests how to best secure your Centreon platform.

Strengthen user account security​

After installing Centreon, it is necessary to change the default passwords of the following users:

  • root
  • centreon
  • centreon-engine
  • centreon-broker
  • centreon-gorgone

To do this, use the following command with a privileged account (eg. sudo) or with root (not recommended — you should have a dedicated user):

passwd <account_name>

In addition, it is important to verify that the Apache account does not have connection rights to the terminal. Execute the following command:

cat /etc/passwd | grep apache

You must have /sbin/nologin like:

apache:x:48:48:Apache:/usr/share/httpd:/sbin/nologin

As a reminder, the list of users and groups can be found here

Enable SELinux​

Centreon recently developed SELinux rules in order to strengthen the control of components by the operating system.

These rules are currently in beta mode and can be activated. You can activate them by following this procedure. In you detect of a problem, it is possible to disable SELinux globally and to send us your feedback in order to improve our rules on Github.

SELinux Overview​

Security Enhanced Linux (SELinux) provides an additional layer of system security. SELinux fundamentally answers the question: May <subject> do <action> to <object>?, for example: May a web server access files in users' home directories?

The standard access policy based on the user, group, and other permissions, known as Discretionary Access Control (DAC), does not enable system administrators to create comprehensive and fine-grained security policies, such as restricting specific applications to only viewing log files, while allowing other applications to append new data to the log files.

SELinux implements Mandatory Access Control (MAC). Every process and system resource has a special security label called an SELinux context. A SELinux context, sometimes referred to as an SELinux label, is an identifier which abstracts away the system-level details and focuses on the security properties of the entity. Not only does this provides a consistent way of referencing objects in the SELinux policy, but it also removes any ambiguity that can be found in other identification methods. For example, a file can have multiple valid path names on a system that makes use of bind mounts.

The SELinux policy uses these contexts in a series of rules which define how processes can interact with each other and the various system resources. By default, the policy does not allow any interaction unless a rule explicitly grants access.

For more information about SELinux please see Red Hat documentation

Activate SELinux in permissive mode​

By default, SELinux is disabled during Centreon installation process. To enable SELinux in permissive mode, you need to modify the /etc/selinux/config file as:

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=permissive
# SELINUXTYPE= can take one of three two values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected.
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

Then reboot your server:

shutdown -r now

Install Centreon SELinux packages​

Depending on the type of server, install the packages with the following command:

yum install centreon-common-selinux \
centreon-web-selinux \
centreon-broker-selinux \
centreon-engine-selinux \
centreon-gorgoned-selinux \
centreon-plugins-selinux

To check the installation, execute the following command:

semodule -l | grep centreon

Depending on your type of server, you can see:

centreon-broker 0.0.5
centreon-common 0.0.10
centreon-engine 0.0.8
centreon-gorgoned   0.0.3
centreon-plugins    0.0.2
centreon-web    0.0.8

Audit logs and enable SELinux​

Before enabling SELinux in enforcing mode, you need to be sure that no errors appear using the following command:

cat /var/log/audit/audit.log | grep -i denied

If errors appear, you have to analyse them and to decide if these errors are regular and must be added in addition of the Centreon default SELinux rules. To do this, use the following command to tranform error in SELinux rules:

audit2allow -a

Then execute the proposed rules.

If after a while, no error is present, you can activate SELinux in full mode by following this procedure using enforcing mode.

Do not hesitate to give us your feedback on Github.

Securing configuration files​

Change the permissions for the following configuration files:

chown centreon:centreon /etc/centreon/conf.pm
chmod 660 /etc/centreon/conf.pm

and

chown apache:apache /etc/centreon/centreon.conf.php
chmod 660 /etc/centreon/centreon.conf.php

Securing the installation of the DBMS​

MariaDB proposes a default procedure to secure the DBMS installation. It is mandatory to set a password for the root user of the database. Please execute the following command and follow instructions:

mysql_secure_installation

Enable firewalld​

Install firewalld:

yum install firewalld

Enable firewalld:

systemctl enable firewalld
systemctl start firewalld

The list of network flows required for each type of server is defined here.

Example of rules for a Centreon Central or Remote Server:

# For default protocols
firewall-cmd --zone=public --add-service=ssh --permanent
firewall-cmd --zone=public --add-service=http --permanent
firewall-cmd --zone=public --add-service=snmp --permanent
firewall-cmd --zone=public --add-service=snmptrap --permanent
# Centreon Gorgone
firewall-cmd --zone=public --add-port=5556/tcp --permanent
# Centreon Broker
firewall-cmd --zone=public --add-port=5669/tcp --permanent

Once the rules have been added, it is necessary to reload firewalld:

firewall-cmd --reload

Enable fail2ban​

Fail2Ban is an intrusion prevention software framework that protects computer servers from brute-force attacks.

Install fail2ban:

yum install epel-release
yum install fail2ban fail2ban-systemd python-inotify

If you have SELinux installed, then update the SELinux policies:

yum update -y selinux-policy*

Enable firewalld:

systemctl enable fail2ban
systemctl start fail2ban

Copy the default rules file:

cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local

Edit /etc/fail2ban/jail.local file and search [centreon] block, then modify such as:

[centreon]
port    = http,https
logpath = /var/log/centreon/login.log
backend  = pyinotify

To enable the centreon fail2ban rule, create the /etc/fail2ban/jail.d/custom.conf file and add following lines:

[centreon]
enabled = true
findtime = 10m
bantime = 10m
maxretry = 3

maxretry is the number of authentication failed before to ban the IP address

bantime is the duration of the ban

findtime is the time range to find authentication failed

Then restart fail2ban to load your rule:

systemctl restart fail2ban

To check the status of the centreon rule you can run:

fail2ban-client status centreon
Status for the jail: centreon
|- Filter
|  |- Currently failed: 1
|  |- Total failed: 17
|  `- File list:    /var/log/centreon/login.log
`- Actions
   |- Currently banned: 0
   |- Total banned: 2
   `- Banned IP list:

For more information go to the official website.

Enable HTTPS on the web server​

By default, Centreon installs a web server in HTTP mode. It is strongly recommended to switch to HTTPS mode by adding your certificate.

It is better to use a certificate validated by an authority rather than a self-signed one. However, in case the self-signed method suits you more, you can refer to the appropriate section.

If you do not have a certificate validated by an authority, you can generate one on platforms such as Let's Encrypt.

Once your web server is set to HTTPS mode, if you have a MAP server on your platform, you have to set it to HTTPS mode too, otherwise recent web browsers may block communication between the two servers. The procedure is detailed here.

Once you have your certificate, perform the following procedure to activate HTTPS mode on your Apache server:

  1. Install SSL module for Apache:
dnf install mod_ssl mod_security openssl
  1. Install your certificates:

Copy your certificate and key on the server according your configuration; by default, it's:

  • /etc/pki/tls/certs/ca.crt
  • /etc/pki/tls/private/ca.key
  1. Backup previous Apache configuration for Centreon:
cp /etc/httpd/conf.d/10-centreon.conf{,.origin}
  1. Edit Centreon Apache configuration

Centreon offers an example configuration file to enable HTTPS available in the following directory: /usr/share/centreon/examples/centreon.apache.https.conf

Edit the /etc/httpd/conf.d/10-centreon.conf as following:

Alias /centreon/api /usr/share/centreon
Alias /centreon /usr/share/centreon/www/

<LocationMatch ^/centreon/(?!api/latest/|api/beta/|api/v[0-9]+/|api/v[0-9]+\.[0-9]+/)(.*\.php(/.*)?)$>
    ProxyPassMatch fcgi://127.0.0.1:9042/usr/share/centreon/www/$1
</LocationMatch>

<LocationMatch ^/centreon/(authentication|api/(latest|beta|v[0-9]+|v[0-9]+\.[0-9]+))/.*$>
    ProxyPassMatch fcgi://127.0.0.1:9042/usr/share/centreon/api/index.php/$1
</LocationMatch>

ProxyTimeout 300

<VirtualHost *:80>
    RewriteEngine On
    RewriteCond %{HTTPS} off
    RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</VirtualHost>

<VirtualHost *:443>
#####################
# SSL configuration #
#####################
    SSLEngine On
    SSLProtocol All -SSLv3 -SSLv2 -TLSv1 -TLSv1.1
    SSLCipherSuite ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-DSS-AES256-GCM-SHA384:DHE-DSS-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-GCM-SHA256:!aNULL:!eNULL:!LOW:!3DES:!MD5:!EXP:!PSK:!DSS:!RC4:!SEED:!ADH:!IDEA
    SSLHonorCipherOrder On
    SSLCompression Off
    SSLCertificateFile /etc/pki/tls/certs/ca.crt
    SSLCertificateKeyFile /etc/pki/tls/private/ca.key

    <IfModule mod_security2.c>
        # https://github.com/SpiderLabs/ModSecurity/issues/652
        SecRuleRemoveById 200003
    </IfModule>

    <Directory "/usr/share/centreon/www">
        DirectoryIndex index.php
        Options Indexes
        AllowOverride all
        Order allow,deny
        Allow from all
        Require all granted
        <IfModule mod_php5.c>
            php_admin_value engine Off
        </IfModule>

        FallbackResource /centreon/index.html

        AddType text/plain hbs
    </Directory>

    <Directory "/usr/share/centreon/api">
        Options Indexes
        AllowOverride all
        Order allow,deny
        Allow from all
        Require all granted
        <IfModule mod_php5.c>
            php_admin_value engine Off
        </IfModule>

        AddType text/plain hbs
    </Directory>
</VirtualHost>

RedirectMatch ^/$ /centreon

Don't forget to change SSLCertificateFile and SSLCertificateKeyFile directives with the path containing your certificate and key.

  1. Enable HttpOnly / Secure flags and hide Apache server signature

Edit the /etc/httpd/conf.d/10-centreon.conf file and add the following line:

Header always edit Set-Cookie ^(.*)$ $1;HttpOnly;Secure;SameSite=Strict
Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"
ServerSignature Off
ServerTokens Prod

Edit the /etc/php.d/50-centreon.ini file and turn off the expose_php parameter:

expose_php = Off
  1. Hide the default /icons directory

Edit the /etc/httpd/conf.d/autoindex.conf file and comment the following line:

#Alias /icons/ "/usr/share/httpd/icons/"
  1. Restart the Apache and PHP process to take in account the new configuration:
systemctl restart php-fpm httpd

Then check its status:

systemctl status httpd

If everything is ok, you must have:

● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/httpd.service.d
           └─php-fpm.conf
   Active: active (running) since Tue 2020-10-27 12:49:42 GMT; 2h 35min ago
     Docs: man:httpd.service(8)
 Main PID: 1483 (httpd)
   Status: "Total requests: 446; Idle/Busy workers 100/0;Requests/sec: 0.0479; Bytes served/sec: 443 B/sec"
    Tasks: 278 (limit: 5032)
   Memory: 39.6M
   CGroup: /system.slice/httpd.service
           ├─1483 /usr/sbin/httpd -DFOREGROUND
           ├─1484 /usr/sbin/httpd -DFOREGROUND
           ├─1485 /usr/sbin/httpd -DFOREGROUND
           ├─1486 /usr/sbin/httpd -DFOREGROUND
           ├─1487 /usr/sbin/httpd -DFOREGROUND
           └─1887 /usr/sbin/httpd -DFOREGROUND

Securing the Apache web server with a self-signed certificate​

Let's assume that we have a Centreon server with a centreon7.localdomain FQDN address.

  1. Preparation of the openssl configuration

Due to a policy change at google, self-signed certificates may be rejected by the google chrome browser. (it is not even possible to add an exception). To continue to use this browser, you have to change the openssl configuration.

open the file /etc/pki/tls/openssl.cnf and find the [v3_ca] section:

# Add the alt_names tag that allows you to inform our various IPs and FQDNs for the server
[ alt_names ]
IP.1 = xxx.xxx.xxx.xxx
DNS.1 = centreon7.localdomain
# If you have several IP (HA: vip + ip)
# IP.2 = xxx.xxx.xxx.xxx
[ v3_ca ]
subjectAltName = @alt_names
  1. Creating a private key for the server

Let's create a private key nammed centreon7.key without a password so that it can be used by the apache service.

openssl genrsa -out centreon7.key 2048

Protect your file by limiting rights:

chmod 400 centreon7.key
  1. Creation of a certificate signing request file

From the key you created, create a CSR (Certificate Signing Request) file. Fill in the fields according to your company. The "Common Name" field must be identical to the hostname of your apache server (in our case it is centreon7.localdomain).

openssl req -new -key centreon7.key -out centreon7.csr
  1. Creation of a private key for the certificate authority's certificate

First, create a private key for this authority. We add the -aes256 option to encrypt the output key and include a password. This password will be requested each time this key is used.

openssl genrsa -aes256 2048 > ca_demo.key
  1. Creation of the x509 certificate from the private key of the certificate authority's certificate

Next, create a x509 certificate that will be valid for one year.

Note that it is necessary to simulate a trusted third party, so the "Common Name" must be different from the server certificate.

openssl req -new -x509 -days 365 -key ca_demo.key -out ca_demo.crt

The certificate being created, you will be able to use it to sign your server certificate.

  1. Creating a certificate for the server

Use the x509 certificate to sign your certificate for the server

openssl x509 -req -in centreon7.csr -out centreon7.crt -CA ca_demo.crt -CAkey ca_demo.key -CAcreateserial -CAserial ca_demo.srl  -extfile /etc/pki/tls/openssl.cnf -extensions v3_ca

The CAcreateserial option is only needed the first time. The previously created password must be entered. You get your server certificate named centreon7.crt.

You can view the contents of the : 

less centreon7.crt
  1. Copy files to apache configuration

Copy the private key of the server and the previously signed server certificate.

cp centreon7.key /etc/pki/tls/private/centreon7.key
cp centreon7.crt /etc/pki/tls/certs/
  1. Update Apache configuration file

Finally, update SSLCertificateFile and SSLCertificateKeyFile parameters appropriately in your apache configuration file located in /opt/rh/httpd24/root/etc/httpd/conf.d/10-centreon.conf. Here is an example of how the file should look like:

Alias /centreon/api /usr/share/centreon
Alias /centreon /usr/share/centreon/www/

<LocationMatch ^/centreon/(?!api/latest/|api/beta/|api/v[0-9]+/|api/v[0-9]+\.[0-9]+/)(.*\.php(/.*)?)$>
    ProxyPassMatch fcgi://127.0.0.1:9042/usr/share/centreon/www/$1
</LocationMatch>

<LocationMatch ^/centreon/(authentication|api/(latest|beta|v[0-9]+|v[0-9]+\.[0-9]+))/.*$>
    ProxyPassMatch fcgi://127.0.0.1:9042/usr/share/centreon/api/index.php/$1
</LocationMatch>

ProxyTimeout 300

<VirtualHost *:80>
    RewriteEngine On
    RewriteCond %{HTTPS} off
    RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI}
</VirtualHost>

<VirtualHost *:443>
    #####################
    # SSL configuration #
    #####################
    SSLEngine on
    SSLProtocol all -SSLv3 -TLSv1 -TLSv1.1
    SSLCipherSuite ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256
    SSLCertificateFile /etc/pki/tls/certs/centreon7.crt
    SSLCertificateKeyFile /etc/pki/tls/private/centreon7.key

    <IfModule mod_security2.c>
        # https://github.com/SpiderLabs/ModSecurity/issues/652
        SecRuleRemoveById 200003
    </IfModule>

    <Directory "/usr/share/centreon/www">
        DirectoryIndex index.php
        Options Indexes
        AllowOverride all
        Order allow,deny
        Allow from all
        Require all granted
        <IfModule mod_php5.c>
            php_admin_value engine Off
        </IfModule>

        FallbackResource /centreon/index

        AddType text/plain hbs
    </Directory>

    <Directory "/usr/share/centreon/api">
        Options Indexes
        AllowOverride all
        Order allow,deny
        Allow from all
        Require all granted
        <IfModule mod_php5.c>
            php_admin_value engine Off
        </IfModule>

        AddType text/plain hbs
    </Directory>
</VirtualHost>
  1. Copy the x509 certificate to the client's browser

Now, you will have to retrieve the certificate file x509 ca_demo.crt and import this file into your browser's certificate manager.

Custom URI​

It is possible to update the URI of Centreon. For example, /centreon can be replaced by /monitoring.

At least one path level is mandatory.

To update the Centreon URI, you need to follow those steps:

  1. Go to Administration > Parameters > Centreon UI and change the Centreon Web Directory value.

image

  1. Edit Apache configuration file for Centreon Web 
vim /etc/httpd/conf.d/10-centreon.conf

Enabling http2​

It is possible to enable http2 protocol to improve Centreon network performance.

To use http2, you need to follow those steps:

  1. Configure https on Centreon

  2. Install nghttp2 module:

dnf install nghttp2
  1. Enable http2 protocol in /etc/httpd/conf.d/10-centreon.conf:
...
<VirtualHost *:443>
    Protocols h2 h2c http/1.1
    ...
</VirtualHost>
...
  1. Update method used by apache multi-processus module in /etc/httpd/conf.modules.d/00-mpm.conf:
-LoadModule mpm_prefork_module modules/mod_mpm_prefork.so
+#LoadModule mpm_prefork_module modules/mod_mpm_prefork.so

-#LoadModule mpm_event_module modules/mod_mpm_event.so
+LoadModule mpm_event_module modules/mod_mpm_event.so
  1. Restart the Apache process to take in account the new configuration:
systemctl restart httpd

User authentication​

Centreon offers several methods to authenticate users:

Create user profiles​

Centreon offers to manage access permissions to the different menus, resources and possible actions on resources via the management of Access Control List.

Secure communications between servers​

It is strongly recommended to secure communications between the different servers of the Centreon platform if some servers are not in a secure network.

The Table of network flows is available here.

Centreon Broker communication​

Centreon Broker and the firewall​

In certain cases, you may not be able to initialize the Centreon Broker data flow from the poller (or the Remote Server) to the Central Server or the Remote Server. See the following configuration to invert the flow.

Centreon Broker flow authentication​

If you need to authenticate pollers that are sending data to the monitoring system, you can use the Centreon Broker authentication mechanism, which is based on X.509 certificates. See the following configuration to authenticate the peer.

Compress and encrypt the Centreon Broker communication​

It is also possible to compress and encrypt the Centreon Broker communication. Go to Configuration > Pollers > Broker configuration menu, edit your Centreon Broker configuration and enable for IPv4 inputs and outputs:

  • Enable TLS encryption: Auto
  • Enable negotiation: Yes
  • Compression (zlib): Auto

Centreon Gorgone communication​

This the official Centreon gorgone documentation to secure the communication.

Security Information and Event Management - SIEM​

Centreon event logs are available in the following directories:

Logs directoryCentral serverRemote ServerPollerCentreon Map serverCentreon MBI Server
/var/log/centreonXX
/var/log/centreon-brokerXXX
/var/log/centreon-engineXXX
/var/log/centreon-gorgoneXXX
/var/log/centreon-biXX
/var/log/centreon-mapXXXX

In addition, all actions to modify the Centreon configuration carried out by users are available via the Administration > Logs menu.

Backing up the platform​

Centreon offers to save the configuration of the platform. To do this, go to the Administration > Parameters > Backup menu.