SANS Issues Top 20 Flaws List

Warns of Microsoft IE, and AV, DNS holes.

The SANS Institute last week issued the first quarterly update to its formerly annual Top 20 Internet Security Vulnerabilities list, which many organizations use as a benchmark to evaluate their network security.

Holes in Microsoft Corp.s software dominate the list, as usual, but SANS also warned about security flaws in popular anti-virus and media player applications, as well as in DNS (Domain Name System).

"We decided that the Top 20 list gets out-of-date too quickly. A lot of organizations use this to measure whether theyre being careful about vulnerabilities, so it has to be kept up-to-date," said Alan Paller, director of research at SANS, in Bethesda, Md.

To make the list, flaws had to meet certain criteria, such as affecting many Internet users and allowing computers to be taken over by a remote, unauthorized user. The holes also had to have been patched in the first three months of this year, Paller said.

"We dont like to tell about vulnerabilities that arent fixed," Paller said. "It helps the bad guys too much."

Holes in products from Microsoft, of Redmond, Wash., include a problem with PNG (Portable Network Graphics) file processing that allows remote attackers to use MSN Messenger to take over vulnerable systems and security flaws in Internet Explorers handling of ActiveX and image files.

The IE holes are particularly dangerous because they are used frequently to place spyware and other malicious code from Web pages into Windows systems without the knowledge of the user, said Gerhard Eschelbeck, chief technology officer at Qualys Inc., of Redwood Shores, Calif. Qualys worked with SANS on the list.

The damage, however, isnt limited to Microsoft. Products from leading security software vendors Symantec Corp., F-Secure Corp., McAfee Inc. and Trend Micro Inc. are also on the updated list. The warnings follow revelations of buffer overflows in those products that could allow remote attackers to take control of systems running the anti-virus software.

Popular media player software, including RealNetworks Inc.s RealPlayer and Apple Computer Inc.s iTunes, also has security vulnerabilities that warrant attention from network administrators, even if the programs arent officially sanctioned for use at work, Paller said.

"People think of these as noncritical software and may not pay attention to updating them," he said.