Unfortunatelly mod-security does not included in this version of Ubuntu, so you have to download it manually.
apt-get install liblua5.1-0 wget http://etc.inittab.org/~agi/debian/libapache-mod-security2/2.5.x/mod-security2-common_2.5.5-1_all.deb wget http://etc.inittab.org/~agi/debian/libapache-mod-security2/2.5.x/libapache2-mod-security2_2.5.5-1_i386.deb dpkg -i mod-security2-common_2.5.5-1_all.deb libapache2-mod-security2_2.5.5-1_i386.deb
mkdir /etc/apache2/modsecurity cp /usr/share/doc/mod-security2-common/examples/rules/*.conf /etc/apache2/modsecurity/
/etc/apache2/modsecurity/modsecurity_crs_10_config.conf
#SecServerSignature "Apache/2.2.0 (Fedora)" SecUploadDir /upload SecAuditLog /var/log/apache2/modsec_audit.log SecDebugLog /var/log/apache2/modsec_debug.log SecDebugLogLevel 0 #SecDataDir /sec_data