Menu
Attackers abuse legacy routing protocol to amplify distributed denial-of-service attacks

Attackers abuse legacy routing protocol to amplify distributed denial-of-service attacks

DDoS attacks can be amplified through SOHO routers that still use the Routing Information Protocol version 1, researchers warn.

Servers could be haunted by a ghost from the 1980s, as hackers have started abusing an obsolete routing protocol to launch distributed denial-of-service attacks.

DDoS attacks observed in May by the research team at Akamai abused home and small business (SOHO) routers that still support Routing Information Protocol version 1 (RIPv1). This protocol is designed to allow routers on small networks to exchange information about routes.

RIPv1 was first introduced in 1988 and was retired as an Internet standard in 1996 due to multiple deficiencies, including lack of authentication. These were addressed in RIP version 2, which is still in use today.

In the DDoS attacks seen by Akamai, which peaked at 12.8 gigabits per second, the attackers used about 500 SOHO routers that are still configured for RIPv1 in order to reflect and amplify their malicious traffic.

DDoS reflection is a technique that can be used to hide the real source of the attack, while amplification allows the attackers to increase the amount of traffic they can generate.

RIP allows a router to ask other routers for information stored in their routing tables. The problem is that the source IP (Internet Protocol) address of such a request can be spoofed, so the responding routers can be tricked to send their information to an IP address chosen by attackers -- like the IP address of an intended victim.

This is a reflection attack because the victim will receive unsolicited traffic from abused routers, not directly from systems controlled by the attackers.

But there's another important aspect to this technique: A typical RIPv1 request is 24-byte in size, but if the responses generated by abused routers are larger than that, attackers can generate more traffic they could otherwise do with the bandwidth at their disposal.

In the attacks observed by Akamai, the abused routers responded with multiple 504-byte payloads -- in some cases 10 -- for every 24-byte query, achieving a 13,000 percent amplification.

Other protocols can also be exploited for DDoS reflection and amplification if servers are not configured correctly, including DNS (Domain Name System), mDNS (multicast DNS), NTP (Network Time Protocol) and SNMP (Simple Network Management Protocol).

The Akamai team scanned the Internet and found 53,693 devices that could be used for DDoS reflection using the RIPv1 protocol. Most of them were home and small business routers.

The researchers were able to determine the device make and model for more than 20,000 of them, because they also had their Web-based management interfaces exposed to the Internet.

Around 19,000 were Netopia 3000 and 2000 series DSL routers distributed by ISPs, primarily from the U.S., to their customers. AT&T had the largest concentration of these devices on its network -- around 10,000 -- followed by BellSouth and MegaPath, each with 4,000.

More than 4,000 of the RIPv1 devices found by Akamai were ZTE ZXV10 ADSL modems and a few hundred were TP-Link TD-8xxx series routers.

While all of these devices can be used for DDoS reflection, not all of them are suitable for amplification. Many respond to RIPv1 queries with a single route, but the researchers identified 24,212 devices that offered at least an 83 percent amplification rate.

To avoid falling victim to RIPv1-based attacks, server owners should use access control lists to restrict Internet traffic on UDP source port 520, the Akamai researchers said in their report. Meanwhile, the owners of RIPv1-enabled devices should switch to RIPv2, restrict the protocol's use to the internal network only or, if neither of those options is viable, use access control lists to restrict RIPv1 traffic only to neighboring routers.


Follow Us

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 akamai

Featured

Slideshows

Reseller News Platinum Club celebrates leading partners in 2019

Reseller News Platinum Club celebrates leading partners in 2019

The leading players of the New Zealand channel came together to celebrate a year of achievement at the annual Reseller News Platinum Club lunch in Auckland. Following the Reseller News Innovation Awards, Platinum Club provides a platform to showcase the top performing partners and start-ups of the past 12 months.

Reseller News Platinum Club celebrates leading partners in 2019
Reseller News hosts alumnae breakfast for Women in ICT Awards

Reseller News hosts alumnae breakfast for Women in ICT Awards

Reseller News hosted its second annual alumnae breakfast for the Women in ICT Awards in New Zealand, designed to showcase the leading female leaders in the industry. Held at The Cordis in Auckland, attendees came together to hear inspiring keynotes and panel discussions, alongside high-level networking among peers. Photos by Gino Demeer.

Reseller News hosts alumnae breakfast for Women in ICT Awards
Reseller News Innovation Awards 2019: meet the winners

Reseller News Innovation Awards 2019: meet the winners

Reseller News honoured the standout players of the New Zealand channel in front of more than 480 technology leaders in Auckland on 23 October, recognising the achievements of top partners, emerging entrants and innovative start-ups.

Reseller News Innovation Awards 2019: meet the winners
Show Comments