Securing OpenEMR - Apache

From OpenEMR Project Wiki

NOTES

  • This tutorial requires a basic understanding of the Linux Terminal and a text editor such as Nano or Vi
  • This tutorial assumes Ubuntu on AWS. Installation elsewhere will likely be very similar.

BASIC

  • Make Apache disclose less information
    • sudo vi /etc/apache2/conf-enabled/security.conf
ServerTokens Prod
ServerSignature Off

SSL


INSTALL WAF / ENABLE MOD_SECURITY

  • Based mainly on this: https://blog.rapid7.com/2017/04/09/how-to-configure-modsecurity-with-apache-on-ubuntu-linux/
  • Install WAF
    • sudo apt-get install libapache2-modsecurity
    • Might have to run: sudo dpkg --configure -a
  • Check Installation
    • apachectl -M | grep security
  • Rename rules
    • mv /etc/modsecurity/modsecurity.conf-recommended /etc/modsecurity/modsecurity.conf
  • Turn rules on
    • sudo vi /etc/modsecurity/modsecurity.conf
    • make sure it reads SecRuleEngine on
  • Remove default rules
    • sudo rm -rf /usr/share/modsecurity-crs
  • Download github rules
  • Rename setup file
    • cd /usr/share/modsecurity-crs
    • sudo mv crs-setup.conf.example crs-setup.conf
  • Add all new rules
    • sudo vi /etc/apache2/mods-enabled/security2.conf
    • place the following block in the document
<IfModule security2_module>
    SecDataDir /var/cache/modsecurity 
    IncludeOptional /etc/modsecurity/*.conf 
    IncludeOptional "/usr/share/modsecurity-crs/*.conf 
    IncludeOptional "/usr/share/modsecurity-crs/rules/*.conf 
</IfModule>
  • Restart apache
    • systemctl restart apache2
  • Raise paranoia level to 2 out of 5
    • sudo vi /usr/share/modsecurity-crs/crs-setup.conf
    • Edit this line to be 2 instead of 1:
      • setvar:tx.paranoia_level=2
  • Test WAF by entering these URLs
    • http://www.<your IP or domain name>/?q="><script>alert(1)</script>
    • http://www.<your IP or domain name>/?q='1 OR 1=1''
    • You should get a 403 error


Enable Mod_Evasive

  • Prevents brute force attempts, spidering, Burp Suite, Nikto, etc
  • This module limits you to X amount of page requests site-wide per interval
  • Install mod_evasive
    • apt-get install libapache2-mod-evasive
  • Create Log
    • sudo mkdir /var/log/mod_evasive
    • chown -R www-data:www-data /var/log/mod_evasive
  • Create blocking script
    • sudo mkdir /etc/apache2/scripts
    • vi /etc/apache2/scripts/ban_ip.sh
#!/bin/sh

IP=$1
IPTABLES=/sbin/iptables

$IPTABLES -A banned -s $IP -p TCP --dport 80 -j DROP
$IPTABLES -A banned -s $IP -p TCP --dport 443 -j DROP

echo "$IPTABLES -D banned -s $IP -p TCP --dport 80 -j DROP" | at now + 3 minutes
echo "$IPTABLES -D banned -s $IP -p TCP --dport 443 -j DROP" | at now + 3 minutes
  • Adjust properties of script
    • sudo chown www-data:www-data /etc/apache2/scripts/ban_ip.sh
    • sudo chmod 550 /etc/apache2/scripts/ban_ip.sh
  • Create mod_evasive config file
    • vi /etc/apache2/mods-enabled/evasive.conf
<IfModule mod_evasive20.c>
    DOSHashTableSize 3097 
    DOSPageCount 5
    DOSSiteCount 50
    DOSPageInterval 1 
    DOSSiteInterval 10 
    DOSBlockingPeriod 180
    #DOSEmailNotify email@yourdomain.com 
    DOSSystemCommand "sudo /etc/apache2/scripts/ban_ip.sh %s'" 
    DOSLogDir "/var/log/mod_evasive" 
</IfModule>
  • Restart Apache
    • sudo apache2 stop
    • sudo apache2 start