What are session IDs or session cookies ?
Talking in simple language, whenever we sign into an account it generates a unique piece of string. One copy is saved on server and other in our browser as cookie. Both are matched every time we do anything in our account. This piece of string or login session is destroyed when we click on 'Sign Out' option.
Just login to yahoo.com. Type in browser javascript:alert(document.cookie);
You would get a pop up box showing you the cookies. Now login to your account and do same thing, you would see more elements added to the cookies. These represent session ids .
Note: By saying , stealing sessions or stealing cookies, I mean the same thing. Sessions are stored in our browser in form of cookies.
An attacker can steal that session by convincing victim to run a piece of code in browser. Attacker can use that stolen session to login into victim's account without providing any username/password. This attack is very uncommon because when the victim clicks 'Sign out' , session gets destroyed and attacker too also gets signed out.
But in case of yahoo, its not the same.The attacker doesnt get signed out when victim clicks 'Sign out'. Though the session automatically gets destroyed after 24hrs by yahoo. But when user simply refreshes the windows in yahoo account, he gets sessions for next 24 hrs. This means, once the yahoo account session is stolen , attacker can access the account for life time by refreshing window in every 24hrs. I am not actually sure whether its 24 or 48 hrs.
Just login to yahoo.com. Type in browser javascript:alert(document.cookie);
You would get a pop up box showing you the cookies. Now login to your account and do same thing, you would see more elements added to the cookies. These represent session ids .
Note: By saying , stealing sessions or stealing cookies, I mean the same thing. Sessions are stored in our browser in form of cookies.An attacker can steal that session by convincing victim to run a piece of code in browser. Attacker can use that stolen session to login into victim's account without providing any username/password. This attack is very uncommon because when the victim clicks 'Sign out' , session gets destroyed and attacker too also gets signed out.
But in case of yahoo, its not the same.The attacker doesnt get signed out when victim clicks 'Sign out'. Though the session automatically gets destroyed after 24hrs by yahoo. But when user simply refreshes the windows in yahoo account, he gets sessions for next 24 hrs. This means, once the yahoo account session is stolen , attacker can access the account for life time by refreshing window in every 24hrs. I am not actually sure whether its 24 or 48 hrs.
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