The vulnerability is in Microsoft Office Excel 2003 Service Pack 2, along with Microsoft Office Excel Viewer 2003, Microsoft Office Excel 2002, Microsoft Office Excel 2000 and Microsoft Excel 2004 for Mac, Microsoft said. If successfully exploited on a vulnerable computer, it could enable remote code execution, the company added.
Microsoft is now investigating public reports and the extent of the vulnerability’s impact on customers. Once that’s done, it may provide a security update through its monthly release process or as an out-of-cycle release, it said.
“While the attack appears to be targeted, and not widespread, we are monitoring the issue and are working with our MSRA (Microsoft Security Response Alliance) partners to help protect customers,” wrote Microsoft’s Security Response Center on the group’s blog. “We will update the advisory and this blog as new information becomes available.”