ActiveX security faces storm before calm

HD Moore is at it again.

Using a custom-built data fuzzing tool, the security researcher pinpointed more than 100 vulnerabilities in the ActiveX controls included with the default installation of Microsoft's Windows XP operating system.

Data fuzzing tools combine knowledge of the input parameters accepted by a software package with a tenacious and systematic mangling of the data to discover how applications react to various permutations, whether valid or invalid.

Moore claims that, while he found more than 100 vulnerabilities in standard ActiveX components, almost another 100 exist in the ActiveX components installed by popular applications, such as Microsoft Office.

While most of the issues discovered by Moore, who is also the founder of the Metasploit Project, are simple denial-of-service problems, about a dozen are remotely exploitable issues in ActiveX controls for Internet Explorer, he said.

"There are a couple of classes that have so many vulnerabilities that I had to black list the entire class," Moore said.

The research underscores the security problems posed by ActiveX controls. ActiveX allows websites to add interactivity and greater functionality to a visitor's browsing experience. However, because the technology allows the website to affect changes on a visitor's PC, the technology also poses a danger.

Online criminals frequently use flaws in ActiveX to install malicious code on victim's browsers. One tool - known as WebAttacker and sold from a Russian website for about $20 - has had great success compromising victims' computers via a flaw in Microsoft's Data Access Components, an ActiveX component fixed in April by Microsoft. The success rate for the tool using that flaw is between 12 per cent and 15 per cent, said Dan Hubbard, vice president of internet security firm Websense.

"People simply aren't updating their browsers," Hubbard said. "Old exploits still work, and on the new exploit front, you can hit a home run with something that works on every browser. The bad guys are getting better at what they are doing."

ActiveX started life as the Object Linking and Embedding (OLE) features created in 1990 to allow Windows applications to exchange data. The general framework became the Component Object Model in 1993 - now known as the Distributed Component Object Model (DCOM)- while Microsoft renamed OLE 2.0 as ActiveX and pushed web developers to add more interactivity to their sites using the technology.

Yet, the software components act as a gateway through which websites can interact with visitors' PCs. And using data-fuzzing tools, finding flaws in key ActiveX components is not difficult. Using such tools, Metasploit's Moore has found enough browser flaws to release a vulnerability every day throughout the month of July.