Introduction

PrivateServer provides a generic interface for Security Information Event management (SIEM), that can be extended to support different SIEM products.

We currently have a connector for HP ArcSight product to monitor security of internal IT assets and trigger proper alarms whenever required. They require that

Security events are stored in

Events are formatted according to CEF specification. It's also possible to log security events locally, in case they cannot be sent to point of delivery.

Glossary

Here some terms used within ArcSight;

• Application: SW component intended to perform core business functionality
• Application Security Configuration Parameter: any configuration item with direct impact on application's security
• Application Security Configuration Target Value: the value of Application Security Configuration Parameter
• Application Security Event: any distinct, time-limited, identifiable activity with direct impact on Application's security
• Application Security Event Message:  the technical log generated by an Application in reaction to Application Security Event
• Monitoring: near real-time validation of Application Security Event Messages, against defined level of escalation (Alert, Record, Log)
• Application Security Scenario: identify patterns with respect to defined conditions and trigger action
• Application Security Scenario Exception: any exception to define scenario
• Escalation level:
  • Alert: requires immediate escalation and quick evaluation
  • Record: to be included in a report for frequent review
  • Log: to be logged with less frequent review

List of events

Here follows the list of generated and logged events.

Pluggable SIEM manager

Given that different customers can have different SIEM systems and/or requirements, we provide a modular and configurable architecture in

The default implementation generated event in CEF format (suitable for HP ArcSight) and, if properly configured, can send them to local rsyslog daemon.

SIEM configuration is available only via manual file editing.

Sender configuration

Sending CEF events works this way: the application servr collects events from event database and logs it using log4j. The logging framework sends events to local rsyslogd daemon, which forward them to remote host, usually ArcSight or another CEF compatible SIEM manager.

Log4j configuration

Edit file /data/shared/privateserver/Config.groovy and insert following snipped:

import log4j.appender.CustodianDailyRollingFileAppender
// standard configuration to send security events to local rsyslog daemon
log4j = {
    appenders {
        appender    new log4j.appender.AdvSyslogAppender(
                name:      "arcsyslog",
                layout:    pattern(conversionPattern: '%m'),
                facility:  "local7",
                tag:       "Privateserver",
                threshold: org.apache.log4j.Level.INFO,
                syslogHost:"localhost",
                header:    true,
                timeZone:  "Europe/Rome"
                )
        appender new CustodianDailyRollingFileAppender(name:'logFile',
                file:"/var/log/tomcat/Privateserver.log",
                datePattern:"'.'yyyy-MM-dd",
                layout: pattern(conversionPattern:'%d [%t] %-5p %c{2} %x - %m%n'),
                compressBackups : 'true',
                maxNumberOfDays : '7')
    }
    root {
        error 'logFile'
    }
    info arcsyslog: "privateserver.siem.CEFSender", additivity : false
}

Once you're done just save the file and restart tomcat service so that it loads new configuration:

systemctl restart tomcat

Rsyslogd configuration

In order to use syslog to receive and forward security events, some changes are required on

1. You first need to enable syslog so to listen on UDP port 514:

   Code Block
   # Provides UDP syslog reception $ModLoad imudp.so $UDPServerRun 514

   
   

2. Configure template format:

   Code Block
   $template EVSSFormat,"<%pri%>%timestamp% %hostname% %syslogtag%%msg%\n"

   
   

3. Redirect all events to a local file (this step is optional and often used for debugging purpose):

   Code Block
   local7.INFO /var/log/arcsight.log;EVSSFormat

   
   

4. Disable boot logging by commenting this line:

   Code Block
   language bash
   # Save boot messages also to boot.log #local7.* /var/log/boot.log

   
   

5. Redirect also all the events to a remote host (please note that "remote-host" has to be changed in actual host's name or IP address to make this work):

   Note
   Be aware that also remote port 514 has to be checked as a valid one. You better receive remote host configuration parameters and then apply them into rsyslog configuration file

   
   

   Code Block
   local7.INFO @@remote-host:514;EVSSFormat

   
   

   Info
   Please take note that @@ means TCP connection, as @ is for UDP one

   
   

Once you're done just save and close /etc/rsyslog.conf. Now you can restart rsyslog so that it loads new configuration:

systemctl restart rsyslog

Customer specific formatter configuration

Security event formatter takes many information as inputs and emits one string containing properly formatted event, ready to be forwarded to SIEM. For specific customers' needs,

If you own yours custom formatter, then you need to enable it appending the following line to file /data/privateserver/Config.groovy so to specify actual formatter class:

  privateserver.siem.formatter = privateserver.siem.CEFCustomFormatter