Go to main content

Oracle® Solaris 11.3 Security and Hardening Guidelines

Exit Print View

Updated: March 2018
 
 

Securing Network Communications

Network communications can be protected by features such as firewalls, TCP wrappers on networked applications, and encrypted and authenticated remote connections.

Packet Filtering

Packet filtering provides basic protection against network-based attacks. Oracle Solaris includes the OpenBSD Packet Filter, the IP Filter feature, and TCP wrappers.

OpenBSD Packet Filter Firewall

The OpenBSD Packet Filter (PF) feature of Oracle Solaris is a network firewall that captures inbound packets and evaluates them for entry to and exit from the system. PF provides stateful packet inspection. It can match packets by IP address and port number as well as by the receiving network interface.

PF is based on OpenBSD Packet Filter version 5.5, which is enhanced to work with Oracle Solaris components, such as zones with exclusive IP instances. In Oracle Solaris 11.3, both PF and IP Filter are available for filtering packets.

IP Filter Firewall

The IP Filter feature of Oracle Solaris creates a firewall to ward off network-based attacks.

Specifically, IP Filter provides stateful packet filtering capabilities and can filter packets by IP address or network, port, protocol, network interface, and traffic direction. It also includes stateless packet filtering and the capability to create and manage address pools. In addition, IP Filter also has the capability to perform network address translation (NAT) and port address translation (PAT).

TCP Wrappers

TCP wrappers provide access control for internet services. When various internet (inetd) services are enabled, the tcpd daemon checks the address of a host requesting a particular network service against an ACL. Requests are granted or denied accordingly. TCP wrappers also log host requests for network services in syslog, which is a useful monitoring function.

The Secure Shell and sendmail features of Oracle Solaris are configured to use TCP wrappers. Network services that have a one-to-one mapping to executable files, such as proftpd and rpcbind, are candidates for TCP wrappers.

TCP wrappers support a rich configuration policy language that enables organizations to specify security policy not only globally but on a per-service basis. Further access to services can be permitted or restricted based upon host name, IPv4 or IPv6 address, netgroup name, network, and even DNS domain.

    For information about TCP wrappers, see the following:

  • How to Use TCP Wrappers

  • For information and examples of the syntax of the access control language for TCP wrappers, see the hosts_access(4) man page.

  • Selected man pages include tcpd(1M) and inetd(1M).

Remote Access

Remote access attacks can damage a system and a network. Oracle Solaris provides defense in depth for network transmissions. Defense features include encryption and authentication checks for data transmission, login authentication, and the disabling of unnecessary remote services.

IPsec and IKE

IP security (IPsec) protects network transmissions by authenticating the IP packets, by encrypting them, or by doing both. Because IPsec is implemented well below the application layer, Internet applications can take advantage of IPsec without requiring modifications to their code.

IPsec and its automatic key exchange protocol, IKE, use algorithms from the Cryptographic Framework. Additionally, the Cryptographic Framework provides a central keystore. When IKE is configured to use the metaslot, organizations have the option of storing the keys on disk, on an attached hardware keystore, or in a software keystore called softtoken. Oracle Solaris supports both the IKE Version 2 (IKEv2) protocol and the IKEv1 protocol.

IPsec and IKE require configuration, so are installed but not enabled by default. When properly administered, IPsec is an effective tool in securing network traffic.

Secure Shell

By default, the Secure Shell feature of Oracle Solaris is the only active remote access mechanism on a newly installed system. All other network services are either disabled or in listen-only mode.

The current Oracle Solaris release includes both the default sunssh implementation of Secure Shell and a new openssh implementation of Secure Shell that is built on OpenSSH 6.5p1 plus additional features.

Secure Shell creates an encrypted communications channel between systems. Secure Shell can also be used as an on-demand virtual private network (VPN) that can forward X Window system traffic or can connect individual port numbers between a local system and remote systems over an authenticated and encrypted network link.

Thus, Secure Shell prevents a would-be intruder from being able to read an intercepted communication and prevents an adversary from spoofing the system.

Kerberos Service

The Kerberos feature of the Oracle Solaris enables single sign-on and secure transactions, even over heterogeneous networks where systems run different operating systems and run the Kerberos service. You can install Kerberos clients by using AI, so that the client is a Kerberized system at first boot.

Kerberos is based on the Kerberos V5 network authentication protocol that was developed at the Massachusetts Institute of Technology (MIT). The Kerberos service offers strong user authentication, as well as integrity and privacy. Using the Kerberos service, you can log in once and access other systems, execute commands, exchange data, and transfer files securely. Additionally, the service enables administrators to restrict access to services and systems.

Copyright © 2011, 2018, Oracle and/or its affiliates. All rights reserved. 
Previous
Next