"The flaw is remotely exploitable," said Mike Puterbaugh, eEye's director of product management.
Although eEye has notified Microsoft of the bug -- and Microsoft has confirmed receipt of the report -- no patch is available. According to eEye, that's not unusual: on average, Microsoft has taken 132 days to patch holes that the Aliso Viejo, Calif.-based security vendor has reported since February 2004.
eEye takes the unique step of logging its reports to Microsoft, then showing the number of days since the vulnerability was confirmed by the Redmond company. After 60 days, it considers a patch "overdue."
Internet Explorer, says eEye, has at least five other critical, but unpatched, vulnerabilities, including ones reported 15, 46, 129, 134, and 171 days ago.
Microsoft has been patching IE regularly, but is having trouble keeping up with the browser's vulnerabilities. In August, it fixed three bugs in the browser, and since the first of the year, has patched IE five out of nine months.