In a 5v5 or 4v4 it's so simple, you just need one or more stunner heroes in your team.
But in 1v1 read here (Link). There are some good comments about that.
Well Ursa isn't that imba, there some easy ways to take him down.
There are a lot of ways to counter Ursa: 1-He has weak lane pressence,so harras him and reduce his farm as much as possible.If he decides to jungle,you should ward his jungle to block creepspawn and make him easier target for gank/ 2-Gank him early.He lacks escape mechanism and his Hp is not that good either. 3-Disables.Disabled Ursa = useless Ursa.If he decides to buy BKB then disables such as Primal Roar will do the job. 4-Ward Roshan to prevent him from obtaining Aegis. 5-Some items like Blademail or Ghost Scepter counter him hard. 6-Most hardcarries beat him late.