Users of IBM's Lotus Notes software have been warned of a dangerous flaw in the Autonomy KeyView software used by the suite to process Lotus 1-2-3 files.

Core Security Technologies said the exploit could allow attackers to run unauthorised software on a victim's PC, with the company's chief technology officer - Ivan Arce – saying it would not be hard for a determined attacker to write code that exploited the flaw. That's because a number of similar KeyView bugs have been found this year, so sample exploit code for similar flaws can easily be found. "Previously there have been other flaws like this published for the same software development kit," he said. "So anyone keeping track of that could write an exploit pretty quickly."

In the past year, security researchers have increasingly focused on these kinds of vulnerabilities, called file parsing bugs. Improvements in hacking software, called fuzzers, which send a barrage of data to programs in order to see if they can be made to act in unexpected ways, have made this type of research easier.

Just last week, researchers at n.runs AG, a German security firm, predicted that parsing vulnerabilities in security software could actually make some products less secure. Researchers Thierry Zoller and Sergio Alvarez have found 80 parser bugs in antivirus software over the past two years. The flaws they've found affect every major antivirus vendor, and many of them could allow attackers to run unauthorized code on a victim's system, the researchers say.

See: Is antivirus software a security threat?

In fact, Symantec recently acknowledged a bug in the KeyView module used by its Symantec Mail Security software. Arce had not tested Symantec's products for this vulnerability, but he said it was quite possibly vulnerable to the flaw as well.

The flaw probably affects other products, according to security experts, because KeyView - which can be used to view and print files in about 300 file formats - is used in many different programs. More than 300 companies, including Symantec and Oracle, have licensed the KeyView software.

IBM acknowledged the problem in a security alert, released Monday, and the company is offering a software patch for Notes 7 users. For those using an older version of Notes, IBM has suggested several workarounds, including deleting the Windows DLL (dynamic link library) file that is associated with Notes.

Autonomy acquired the KeyView software as part of its $500m purchase of search software vendor Verity, completed in late 2005.

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