Users of the latest versions of Microsoft"s popular MSN Messenger program are vulnerable to computer hackers, the company warned on Wednesday.
The vulnerability was discovered as Microsoft undergoes an intensive company-wide campaign to stamp out security problems, an effort ordered by chairman and chief software architect, Bill Gates.
The latest problem is in a feature that allows users to gather in a single virtual location or "chat room" to exchange messages across the Internet in almost real time.
Affected software includes Microsoft MSN Chat Control, Microsoft MSN Messenger versions 4.5 and 4.6, and Microsoft Exchange Instant Messenger 4.5 and 4.6.
Microsoft has been trying to make inroads into the market dominated by AOL"s Instant Messenger.