For Cordova 2.7.0 you will need Xcode 4.5 or higher. Then just install the Cordova SDK.
You will need to be running OSX Lion or higher.
Question
Can anyone please tell me how to upgrade Cordova Framework from 1.5.0 to 2.7.0 in XCode ? I am using XCode version 4.3.2
Solution
For Cordova 2.7.0 you will need Xcode 4.5 or higher. Then just install the Cordova SDK.
You will need to be running OSX Lion or higher.