More and more organizations are implementing DNSSEC on their name servers. But the actual number of signed zones is very low, leaving these organizations vulnerable to cache poisoning attacks.
While organizations are beginning to adopt DNSSEC (Domain
Name System Security Extensions) to secure their Websites, many of them are
not correctly implemented or maintained according to specifications, according
to a survey released by Infoblox on Dec. 6.
The sixth annual survey of domain name server
infrastructure on the Internet is a "census of name servers," said
Cricket Liu, vice president of architecture at Infoblox, to eWEEK. The survey
identified 15.6 million name servers on the Internet and included only the
.org, .com and .net domains, said Liu.
of the DNS Security Extensions
jumped a dramatic 340 percent from 2009, the
actual number of "zones" that have been signed is less than 1
percent, according to the survey. Considering that organizations went through
the trouble of setting up the DNSSEC on their name servers, the fact that only
0.022 percent of the zones were actually signed was "surprisingly high"
and a "clear indicator" they weren't configuring or maintaining them
correctly, Liu said. In 2009, the number was even smaller, at 0.005 percent, he
DNSSEC is a set of security extensions that authenticate
DNS data to ensure that the Web servers the public connects to are authentic
and not run by malicious imposters. In a cache
attack, a cyber-criminal directs users to a different Website
without their realizing it, as happened to Kaspersky
Labs earlier this year. Without implementing DNSSEC, organizations on the Web
are vulnerable, said Liu.
Among the three surveyed domains, .org sites had a higher
rate of DNSSEC implementations because the TLD
(Top-Level Domain) began supporting DNSSEC earlier this year, said Liu. VeriSign
is expected to sign for .net this week, and .com should be signed in the spring
of 2011, said Liu. He said the situation is "likely to change" in
next year's survey as more TLDs are signed.
Government domains, .gov, are counted in a different
survey, and their adoption rates are "pretty high," in the
neighborhood of "20 percent," said Liu.
However, of the tiny number of zones that are
DNSSEC-signed, 23 percent of them failed validation because the signatures had
expired, the survey found. If the process of deploying and re-signing DNSSEC
was automated, having the zone expire would be less likely, said
The DNSSEC implementation was faulty in many cases, as
only 81.4 percent of the name servers permitted TCP
queries and 26.4 percent didn't support EDNS0 (Extension mechanisms for DNS),
according to the survey. Both TCP queries
and EDNS0 are required for DNSSEC, Liu said.
Despite warnings over the "vulnerability" of
DNS and a "long history" of downtime associated with DNS issues, "organizations
are still not taking DNS security seriously," Liu said.
Most of the implementations were "science projects,"
as companies took DNSSEC out for a test drive to see what it does, said
Even so, the survey had some positive name server results.
The number of servers with Sender Policy Framework (SPF)
to identify and reject spam increased from 12.2 percent last year to 15.9
percent, according to the survey. The number of servers misconfigured to allow
zone transfers, which exposes them to denial-of-service attacks, dropped to
11.3 percent, from 15.8 percent last year, in the survey.
Other networking experts frequently raise the alarm over
the lack of security in DNS. Craig Labovitz, chief scientist at Arbor Networks,
said Internet traffic was routed on a system relying "primarily on trust"
and had no security standards. He said the world was on "borrowed
time" before a serious incident occurred.
"We are nowhere near what's required to prevent
criminals from wreaking havoc with online business," Liu said.
The survey results, along with recent outages, such as Comcast's
on Nov. 28, should be a "huge wake-up call" for
organizations online, said Liu.
Organizations need to assess existing DNS infrastructure
and "immediately" take steps to secure them, said Liu. Administrators
should upgrade to the most recent version of BIND, separate internal and
external name servers, separate authoritative and recursive name servers from
each other, and randomize ports to defend against cache poisoning attacks,
according to Infoblox.
The survey also found the number of zones with at least
one IPv6 name server is almost double the number from 2009, indicating the
there is some movement, slowly, to IPv6, Infoblox said.
"2011 has to be the year for DNSSEC deployment or
organizations will have no one to blame but themselves if they become victims,"