Yahoo resumed promoting a Yahoo Messenger upgrade on Monday after fixing a bug in the program that altered users' e-mail preferences without their consent.
The bug was discovered on Friday, when Yahoo started prompting Yahoo Messenger users to upgrade to version 8.1. The bug automatically set Yahoo Mail as users' default e-mail system.
Yahoo fixed the program's installer on Friday, tested it over the weekend and on Monday reactivated the Yahoo Messenger 8.1 automatic upgrade notification process, a Yahoo spokeswoman said.
Among the enhancements in Yahoo Messenger 8.1 is a security update that patches a hole that could allow a malicious hacker to exploit a buffer overflow tied to an ActiveX control that is typically downloaded with the IM software, the spokeswoman said.
Yahoo isn't aware of any exploits related to this security hole, but it nevertheless encourages all Yahoo Messenger users to update to version 8.1, she said.