Microsoft is forcing users of its MSN and Live instant messenger (IM) software to upgrade to the latest version to address a serious security vulnerability.
The company issued a patch for the vulnerability, which could allow remote code execution when a user accepts a webcam or video chat invitation from an attacker, earlier this week as part of its regular monthly set of patches.
Microsoft said an attacker who successfully exploited this vulnerability could potentially take complete control of the affected system.
Having issued the patch on Tuesday, allowing users of affected versions, 6.2, 7.0 and 7.5 versions of MSN Messenger or Windows Live Messenger 8.0 to address the vulnerability, Microsoft has now decided to force an upgrade to the unaffected Windows Live version 8.1 for all users of affected versions.
"Some of you might feel this inconvenient, but in order to protect you and protect the health of the network we have chosen to take this step," said a blog entry posted by a security product manager for Windows Live Messenger.
Affected users were invited to download the latest version prior to the patch release, but will now be notified to upgrade at each attempt to sign on to the service. The Microsoft blog posting said users who do not accept the upgrade notification will be blocked from accessing the service.
Microsoft changed the name of the chat client from MSN Messenger to Windows Live with version 8.0. But some users responding to the blog posting were unhappy with the mandatory upgrade, saying the latest version does not compare favourably with older ones because, for instance, it requires greater computing resources to run audio and video features.
One user wrote: "It's my computer and I should be allowed to do what I want with it. I don't want to be forced into upgrading to Windows Live, when I find 7.5 a much better choice."
