The flaw is in an ActiveX control included with Windows 2000, Windows XP, and Windows Server and can be exploited to overflow Internet Explorer's buffer, then introduce malicious code to the compromised PC.
A working exploit against yet another unpatched bug in Internet Explorer has popped up, security researchers, including those at US-CERT, said Thursday.
"Now that a functional exploit is available, an official patch from Microsoft will likely appear at some point in the future," Symantec said in an alert to customers.
That may be whistling in the dark, however, since Microsoft has several outstanding vulnerabilities to contend with, including the earlier ActiveX flaw and one publicized Wednesday in Microsoft Office's presentation software, PowerPoint.
Microsoft has not posted an advisory for the new flaw, and Symantec and US-CERT only suggested that users either disable Active Scripting in IE or set the "kill bit" for the ActiveX control. The latter, however, is somewhat technical and if done incorrectly, can damage the operating system.
5 Top Federal Initiatives For 2015As InformationWeek Government readers were busy firming up their fiscal year 2015 budgets, we asked them to rate more than 30 IT initiatives in terms of importance and current leadership focus. No surprise, among more than 30 options, security is No. 1. After that, things get less predictable.