Stealing Cookie With XSS

[z3ro]

Suppose Mr. A has stolen the cookies of Mr. X  .... so what?? 
what the hell can he do with it?   

[Kulverstukas]

Depends on the cookie type. If the cookie is tangible - you can eat it.
If the cookie is virtual, you can browse the website with some guys session (logged in as that user) without the victim knowing, until the sessions ends of course.
Kinda hard to answer if you don't know the concepts of networking.

[z3ro]

Depends on the cookie type. If the cookie is tangible - you can eat it.
If the cookie is virtual, you can browse the website with some guys session (logged in as that user) without the victim knowing, until the sessions ends of course.
Kinda hard to answer if you don't know the concepts of networking.

most website (facebook, twitter, ymail, gmail, etc) use httpOnly cookies.... >> which are virtually not 'stealable' using js.