Cloud

8/16/2016
05:10 PM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%

Poorly Configured DNSSEC = Potential DDoS Weapon

New research from Neustar shows how attackers could abuse DNSSEC-secured domains for distributed denial-of-service (DDoS) attacks.

Just because a domain is signed with DNSSEC security doesn’t mean a Domain Name System (DNS) server is immune to abuse, according to new research.

Neustar studied nearly 1,350 domains with DNSSEC deployed and found that 80% of them could be used to amplify distributed denial-of-service (DDoS) attacks, at an average factor of 28.9 times. That’s because the domains hadn’t properly deployed DNSSEC-signing of their domains, leaving them vulnerable to DDoS abuse. Neustar ran DNS queries from four different open recursive servers to find name servers that responded to queries via the ANY query feature in DNS.

“On average, they returned [responses] 29 times” a normal response, says Joe Loveless, director of security services product marketing at Neustar. “That’s a lot of payback for an attacker who wants amplification.”

Neustar this year also has spotted a large number of actual attacks that take advantage of poorly deployed DNSSEC, he says.

DNS security expert Dan Kaminsky says the real problem lies within DNS, not DNSSEC. “There's a bug, we need to fix it. It's not in DNSSEC and it's kind of not in DNS. We need to be able to track spoofed floods and automate the rate limiting of them,” Kaminsky says.

Neustar’s Loveless concurs with Kaminsky, and adds that it’s more about the administration and deployment of DNSSEC—not its functionality—that’s at risk. “Attackers are exploiting the amplification factors available to them in poorly managed DNSSEC use to create attacks more quickly and more practically,” Loveless says.

Neustar found in its test that the DNSSEC-protected domains in question could be abused to turn an 80-byte query into a 2,313-byte response, which it says could easily could knock a network offline.

DNSSEC signs a domain to provide authentication and verification. The digital signature and key exchange information, in addition to ANY responses, adds up to a bigger amount of traffic than a non-DNSSEC DNS response, according to Neustar. “The record sizes are larger than simple DNS reflection or proper amplification attacks,” Loveless says.

Kaminsky, meanwhile, says there are plenty of amplification attacks against DNS domains that don’t have DNSSEC. “It's called an ANY request because ANY record can be returned, and ANY record can contain ANY information desired by an attacker,” he says.

The Net needs a way to thwart faked traffic sources, says Kaminsky, who is co-founder and chief scientist of WhiteOps.

DDoS threats to DNS are not new. Kaminsky in 2011 blogged that while it’s easy to blame DNSSEC for these flooding DDoS attacks, it’s more of an underlying IP problem of trust and acceptance, and DNS itself is vulnerable to amplification attacks. 

The best defense from DNS DDoS attacks, according to Loveless, is for DNS providers to filter for abuse or not to respond to “ANY” queries. 

Related Content:

Kelly Jackson Higgins is Executive Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Crowdsourced vs. Traditional Pen Testing
Alex Haynes, Chief Information Security Officer, CDL,  3/19/2019
BEC Scammer Pleads Guilty
Dark Reading Staff 3/20/2019
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: Insider Threat Prevention activated!
Current Issue
5 Emerging Cyber Threats to Watch for in 2019
Online attackers are constantly developing new, innovative ways to break into the enterprise. This Dark Reading Tech Digest gives an in-depth look at five emerging attack trends and exploits your security team should look out for, along with helpful recommendations on how you can prevent your organization from falling victim.
Flash Poll
The State of Cyber Security Incident Response
The State of Cyber Security Incident Response
Organizations are responding to new threats with new processes for detecting and mitigating them. Here's a look at how the discipline of incident response is evolving.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2019-7238
PUBLISHED: 2019-03-21
Sonatype Nexus Repository Manager before 3.15.0 has Incorrect Access Control.
CVE-2017-16253
PUBLISHED: 2019-03-21
An exploitable buffer overflow vulnerability exists in the PubNub message handler Insteon Hub 2245-222 - Firmware version 1012 for the cc channel of Insteon Hub running firmware version 1012. Specially crafted commands sent through the PubNub service can cause a stack-based buffer overflow overwriti...
CVE-2017-16254
PUBLISHED: 2019-03-21
An exploitable buffer overflow vulnerability exists in the PubNub message handler Insteon Hub 2245-222 - Firmware version 1012. Specially crafted commands sent through the PubNub service can cause a stack-based buffer overflow overwriting arbitrary data. An attacker can send an authenticated HTTP re...
CVE-2017-16255
PUBLISHED: 2019-03-21
An exploitable buffer overflow vulnerability exists in the PubNub message handler Insteon Hub 2245-222 - Firmware version 1012. Specially crafted commands sent through the PubNub service can cause a stack-based buffer overflow overwriting arbitrary data. An attacker can send an authenticated HTTP re...
CVE-2018-3968
PUBLISHED: 2019-03-21
An exploitable vulnerability exists in the verified boot protection of the Das U-Boot from version 2013.07-rc1 to 2014.07-rc2. The affected versions lack proper FIT signature enforcement, which allows an attacker to bypass U-Boot's verified boot and execute an unsigned kernel, embedded in a legacy i...