DNS Attacks Expose Key Flaws

By Paul F. Roberts  |  Posted 2005-05-02

The steady rise in phishing attacks in the last year, coupled with increasingly sophisticated scams such as "pharming" attacks, is driving interest in technology to lock down critical components such as e-mail and Domain Name System.

But bigger changes to the underlying Internet infrastructure may be needed, according to interviews with industry experts who will be addressing the issue at the Interop show in Las Vegas this week.

Reports of phishing attacks grew an average of 26 percent each month between July of last year and February of this year, according to the Anti-Phishing Working Group, an industry association.

In recent weeks, APWG and The SANS Institutes Internet Storm Center warned of new attacks such as "pharming," or "phishing without a lure," that attack DNS servers and silently route unsuspecting Web surfers to phishing Web sites, or sites that download malicious code.

The new attacks expose weaknesses in critical Internet infrastructure such as DNS, said Mike Hyatt, president and CEO of BlueCat Networks Inc., which makes secure hardware appliances for DNS and DHCP (Dynamic Host Configuration Protocol).

BlueCat will use Interop to preview an extension to its Adonis line of secure DNS and DHCP appliances.

"The paradox of DNS is that everybody knows it, but only a few people know anything about it," Hyatt said.

Recent pharming attacks have taken advantage of old and insecure implementations of BIND (Berkeley Internet Name Domain) technology, the dominant DNS software used on the Internet, and vulnerable default configurations on some versions of Windows 2000 systems that were acting as DNS servers, according to the Internet Storm Center.

"These attacks are pretty blatant," said Paul Mockapetris, the inventor of DNS and now chief scientist at Nominum Inc., a provider of Internet name and address services based in Redwood City, Calif., who will be on an Interop panel concerning emerging threats.

"What we need to do is move to a secure DNS architecture, but that will take a while," Mockapetris said.

The recent Internet Systems Consortium BIND Version 9 release solved many of the security problems exploited in the recent attacks, but companies still fall victim to bad implementations, said Joe Briante, senior systems engineer at BlueCat.

Failing to take simple steps, such as setting up separate DNS servers for internal and external use or maintaining a redundant DNS server, can spell disaster, Hyatt said.

"When you take down DNS, its lights out because there are lots of things you take down with it: firewall, e-mail. People dont think about it," Hyatt said.

Mockapetris agreed, saying that administrators need to pay more attention to issues such as DNS server configuration. "People tend to configure stuff until it works, then they call it a day. But thats not where the real world is today," he said.

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