• Home
• Topics
• Enterprise Data Protection
• Enterprise Data Governance
• How to protect DNS servers

How to protect DNS servers

Requires Free Membership to View

Login



SearchSecurity.com members gain immediate and unlimited access to breaking industry news, virus alerts, new hacker threats, highly focused security newsletters, and more -- all at no cost. Join me on SearchSecurity.com today!

Michael S. Mimoso, Editorial Director

• E-mail Address: 

By submitting your registration information to SearchSecurity.com you agree to receive email communications from TechTarget and TechTarget partners. We encourage you to read our Privacy Policy which contains important disclosures about how we collect and use your registration and other information. If you reside outside of the United States, by submitting this registration information you consent to having your personal data transferred to and processed in the United States. Your use of SearchSecurity.com is governed by our Terms of Use. You may contact us at webmaster@TechTarget.com.

As a network administrator, your task is to make it is as difficult as possible for attackers to compromise or hijack your DNS servers. If your DNS data is compromised, hackers can obtain information about your network that can be used to damage other Web services. For example, if attackers can change your DNS zone data, which includes domain names, computer names, and IP addresses for sensitive network resources, they can set up fake Web servers or cause email to be redirected to other servers.

To protect a server, first develop a DNS security policy. Decide what access your clients need and what data you most want to protect. It will help to review name-resolution traffic to see which clients can query which servers. Then decide what level of security is needed, as there is a trade-off between security and performance. If Internet connectivity is not required, DNS servers can be made much more secure. In this scenario, your network only requires an internal DNS root and namespace, and all authority for DNS zones is internal. It's unlikely, however, that you are in this position.

I would recommend locating DNS servers behind a separate firewall that isn't connected to your network. Because there is no direct connection, this arrangement protects your network should one of your DNS servers be compromised.

If the budget allows, configure a third DNS server to act as the master DNS server. The master would not have a public IP address and would be configured to only talk to the two forward-facing secondary DNS servers. Since the DNS information on the master server can't be directly changed, any unauthorized changes on the secondary servers would only last until the next time they receive an update from the master. All updates should be sent only via a secure connection.

Beyond simply using firewalls to control DNS access, you should also set access controls on DNS registry entries and file system entries.

For more information about DNS vulnerabilities, I recommend reading RFC 3822, which is a threat analysis of the Domain Name System. There's also, DNSSEC (DNS Security Extensions), a set of extensions that aim to improve the security of DNS. DNSSEC modifies DNS to add support for cryptographically signed responses. There are various other extensions to support the security of zone transfer information as well.

Even encryption doesn't prevent the possibility that a DNS server could become infected with a virus, so server hardening is a key step to protecting them. Finally, the resources at www.dnsreport.com can test a given domain and provide comprehensive information about possible DNS security issues.

More information:

Dig Deeper

This was first published in February 2008

More from Related TechTarget Sites

• Security Channel
• Cloud Security
• SMB Security
• Financial Security
• Security UK
• Security AU
• Security IN

• Security Channel

  • Survey results: VARs report customers’ IT spending 2012 expectations

    VARs expect customers to increase spending on security more than any other IT area in 2012. See which security segments will grow the most.

  • Create a computer security blog to attract and retain customers

    Blogging can produce new leads for security solution providers. Focus on content in your computer security blog that connects with customers.

  • Penetration testing tutorial: Guidance for effective pen tests

    This penetration testing tutorial contains essential tips to help solution providers uncover vulnerabilities in clients’ networks.

• Cloud Security

  • Are cloud providers HIPAA business associates?

    Deciding whether your cloud provider is a business associate comes down to a judgment call based on the type of cloud usage.

  • SaaS security: Weighing SaaS encryption options

    A look at SaaS encryption techniques and challenges.

  • Panel debates cloud computing governance issues

    Problems with data governance in the cloud aren’t much different than traditional outsourcing.

• searchMidmarketSecurity

  • Windows Phone 7 security: Assessing WP7 security features

    Windows Phone 7 security features are proving to be a mixed bag. Sam Cattle assesses the enterprise security pros and cons of the latest Windows mobile platform.

  • Choosing the best security certifications for your career

    Whether starting your career or planning your next step as an IT security professional, this tip will guide you toward the best certifications for your interests and experience.

  • Midmarket security tutorials

    SearchMidmarketSecurity.com’s tutorials offer IT professionals in-depth lessons and technical advice on the hottest topics in the midmarket IT security industry. Through our tutorials we seek to provide site members with the foundational knowledge needed to deal with the increasingly challenging job of keeping their organizations secure.

• searchFinancialSecurity

  • Web application threats: What you really need to know

    In this special presentation, Mike Rothman details today's top Web application threats and pragmatic methods to integrate security into the Web application development process.

  • Ramnit worm variant now dangerous banking malware

    The Ramnit worm now supports man-in-the-middle attacks, giving cybercriminals the ability to drain a victim’s bank account.

  • SIEM vendors make the case for extending SIEM product capabilities

    Advanced features can reduce the threat of wire fraud. New rule sets can be shared among banks and credit unions.

• Security UK

  • Study finds attacks slip past spotty patch management policies

    A study finds attackers targeting firms with poor patch management policies, exploiting vulnerabilities that should have been patched years ago.

  • Survey: Types of DDoS attacks on the rise due to hacktivist groups

    New DDoS statistics suggest hactivist groups are to blame for an increase in the number and types of DDoS attacks across the Internet.

  • Web application vulnerability statistics show security losing ground

    New Web application vulnerability statistics show the number of vulnerabilities is rising, despite the use of Web application development frameworks.

• searchSecurityAU

  • AISA launches new website

    With a reinvigorated look and feel, improved back-end infrastructure, and regularly updated information about the association the Australian Information Security Association website has been re-launched for the benefit of its members and the Australian IT Security industry.

  • Cisco hardening guides for IOS, IOS-XR and NX-OS devices

    Patching routing and switching infrastructure in any organisation is often delayed, sometimes due to the potential impact on production systems and sometimes because the IT resources are simply too busy fighting fires.

  • Cloud providers and data sovereignty issues

    Australian cloud provider Ninefold warn that understanding who has legal access to company and personal private data is not as simple as checking a box and selecting the 'in-country' option.

• Information Security

  • Airtel’s DLP technology rollout makes data egress a thing of the past

    Airtel’s DLP technology implementation, India’s largest, went live in December 2010. Join us in exploring its inner workings, even as it is poised for bigger things.

  • February 2012 Patch Tuesday to address 21 vulnerabilities

    Microsoft plans to fix coding errors in Internet Explorer, .NET Silverlight and Microsoft Office.

  • IDFC’s information security awareness week tastes success with ‘Mr Gobo’

    Financial major IDFC set out to craft its information security awareness initiative with a portal that led users via a ‘Mafia don’s den’. Step in for more.

• About us
• Contact us
• Site index
• Privacy policy
• Advertisers
• Business partners
• Events
• Media kit
• TechTarget corporate site
• Reprints
• Site map