LPI LVL3 Security: Area 3 Network Security



Deals with security issues that mainly use the network user and authentication systems such as NIS/Kerberos, Samba, Inetd/Xinetd, Linux firewalling (iptables and ipchains), NAT, Performing vulnerability, assessments, email security (relay, mimedefang, TLS), SSH, NMAP, Nessus, Ethereal, etc.


  1. Network security systems


    1. Network authentication / enterprise directories

                                                               i.      NIS / YP

                                                             ii.      Kerberos

                                                            iii.      Samba (?)

                                                           iv.      PAM Plug-ins


    1. Linux firewalling and routing

                                                               i.      Routing and routing tables

1.      Security through routes to nowhere

2.      Static routes

3.      Dynamic routing software (BCP, RIP, etc.)

                                                             ii.      Iptables

                                                            iii.      Ipchains

                                                           iv.      Understanding NAT / Masquerading

                                                             v.      /etc/hosts

                                                           vi.      /etc/services




    1. NTPD


    1. Superserver security

                                                               i.      Inetd

                                                             ii.      Xinetd

                                                            iii.      Trivial services

                                                           iv.      tftpd


    1. FTP security

                                                               i.      No anonymous write

                                                             ii.      Sandboxed FTP daemon

                                                            iii.      Extensive logging

                                                           iv.      Change /etc/shells so FTP-only users cannot log in


    1. Mail Security

                                                               i.      SMTP relay

                                                             ii.      SMTP auth

                                                            iii.      SSL / TLS

                                                           iv.      POP2 / POP3 vs. IMAP

                                                             v.      MIMEDEFANG

                                                           vi.      Postfix filters


    1. Web Application Security

                                                               i.      Common security flaws

1.      O/S or Daemon security risks

2.      Cross-Site Scripting

3.      SQL Injection

4.      Use of client-side scripting

5.      Use of hidden form inputs

6.      Use of cookies

7.      Session and state tracking

8.      In-line comments

9.      Default scripts / server config

                                                             ii.      Resources

1.      OWASP


    1. Remote security

                                                               i.      Perform a vulnerability assessment in alignment with OSSTMM

                                                             ii.      Performing a vulnerability assessment with Nessus

                                                            iii.      Running NMAP

                                                           iv.      Running nikto