Academic institutions urged to take steps to prevent DNS amplification attacks

REN-ISAC advises members to secure their DNS servers and implement network filtering to prevent spoofing

Colleges and universities are being encouraged to scrutinize their systems to keep them from being hijacked in DDoS (distributed denial-of-service) attacks.

The Research and Education Networking Information Sharing and Analysis Center (REN-ISAC) advised academic institutions this week to review their DNS (Domain Name System) and network configurations in order to prevent their systems from being abused to amplify DDoS attacks.

"The REN-ISAC wants to raise awareness and drive change concerning common network and domain name system (DNS) configurations that fall short of accepted best practice and which, if left unchecked, open the door for your institution to be exploited as an unwitting partner to crippling denial of service attacks against third parties," said Doug Pearson, technical director of REN-ISAC, in an alert sent Wednesday to the organization's members.

REN-ISAC's members include over 350 universities, colleges and research centers from the U.S, Canada, Australia, New Zealand and Sweden.

The DDoS attacks Pearson refers to are known as DNS amplification or DNS reflection attacks and involve the sending of DNS queries with a spoofed IP (Internet Protocol) address to recursive DNS resolvers that accept queries from outside of their networks.

These spoofed requests result in considerably larger responses sent by the queried "open" DNS resolvers to the IP addresses of the intended victims, flooding them with unwanted traffic.

This attack method has been known for many years and was recently used to launch a DDoS attack of unprecedented scale that reportedly peaked at over 300Gbps against a spam-fighting organization called Spamhaus.

"To put that in context, most universities and organizations connect to the Internet at 1 Gbps or less," Pearson said. "In this incident not only was the intended victim crippled, Internet service providers and security service providers attempting to mitigate the attack were adversely affected."

"The higher education and research community needs to do its part to ensure that we are not helping to facilitate these attacks," Pearson said.

REN-ISAC issued two versions of the alert, one meant for CIOs that contained more general information about the threat, and one directed at IT security staff, as well as network and DNS administrators, containing technical advice on how to mitigate the problem.

The recommendations included configuring recursive DNS resolvers to only be accessible from the organization's networks, enforcing query rate limits for authoritative DNS servers that do need to be queried from external networks and to implement the anti-spoofing network filtering methods defined in IETF's Best Current Practice (BCP) 38 document.

It's admirable that REN-ISAC is taking this step of notifying its members and educating them about this problem, said Roland Dobbins, a senior analyst in the security engineering and response team at DDoS mitigation vendor Arbor Networks. Other industry associations should do so as well, he said.

By their nature, academic institutions tend to be more open with their access policies and haven't necessarily hardened everything to a degree that would ensure their servers can't be abused, Dobbins said. Arbor has seen open DNS resolvers on all kinds of networks including educational ones, that were used to launch DNS reflection attacks, he said.

However, it's important to understand that DNS reflection attacks are only one type of amplification attack, Dobbins said. Other protocols including SMTP (Simple Mail Transfer Protocol) and NTP (Network Time Protocol) can be abused in a similar way, he said.

Securing and properly configuring DNS servers is important, but it's even more important to implement BCP 38, Dobbins said. Anti-spoofing should be applied on all Internet-facing networks so that spoofed packets cannot originate from them. "The closer we get to universal application of BCP 38, the harder it becomes for attackers to launch DDoS amplification attacks of any kind."

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags online safetyarbor networksAccess control and authentication

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lucian Constantin

IDG News Service
Show Comments

Cool Tech

Toys for Boys

Family Friendly

Stocking Stuffer

SmartLens - Clip on Phone Camera Lens Set of 3

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Michael Hargreaves

Microsoft Office 365/Dell XPS 15 2-in-1

I’d recommend a Dell XPS 15 2-in-1 and the new Windows 10 to anyone who needs to get serious work done (before you kick back on your couch with your favourite Netflix show.)

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?