Generally speaking, when given a cookie that has no expiration period, modern browsers will consider this cookie to be a 'session cookie', they will remove the cookie at the end of the browsing session (generally when the browser instance closes).
IE, Opera, Safari and Chrome all support this behavior.
However firefox (3.0.9 latest proper release) appears not to follow this rule, from what I can tell it doesn't expire the cookies when the browser is closed, or when the user logs off or restarts the OS..
So, why does firefox refer to these as session cookies, when they last aparently indefinitely?
Does anyone know how Firefox handles session cookie expiration?
This is apparently by design. Check out this Bugzilla bug:
https://bugzilla.mozilla.org/show_bug.cgi?id=443354
Firefox has a feature where you close Firefox and it offers to save all your tabs, and then you restore the browser and those tabs come back. That's called session restore. What I didn't realize is that it'll also restore all the session cookies for those pages too! It treats it like you had never closed the browser.
This makes sense in the sense that if your browser crashed you get right back to where you were, but is a little disconcerting for web devs used to session cookies getting cleared. I've got some old session cookies from months ago that were set by sites I always have open in tabs.
To test this out, close all the tabs in your browser, then close the browser and restart it. I think the session cookies for your site should clear in that case. Otherwise you'd have to turn off session restore.
Two ideas :
You have a problem with your session manager (the one included in FF3 or one included in an extension, like tabmixplus)
Use Firebug + FireCookie (https://addons.mozilla.org/en-US/firefox/addon/6683) to debug !
This should work. I used to be one of the cookie module testers, and I don't think there is any design reason this would behave differently (although if you crash, the session cookies might be designed to live on when you restart...)
Are you viewing the cookies in the "Preferences" menu > "Privacy" Tab > "Show Cookies..." button?
Also, have you tried a new profile?
I disagree with meandmycode above.
The HTTP spec https://www.ietf.org/rfc/rfc6265.txt talks about what a client should do with Set-Cookie headers with Expires:
If the server wishes the user agent to persist the cookie over multiple "sessions" (e.g., user agent restarts), the server can specify an expiration date in the Expires attribute. Note that the user agent might delete the cookie before the expiration date if the user agent's cookie store exceeds its quota or if the user manually deletes the server's cookie.
The logical extension of this is that the ONLY way the server has to require that the browser does not maintain a Cookie on exit is to set no Expires value (i.e a session cookie). If a browser does not honor that semantic then its not honoring the server's response.
Essentially the user agent is deciding to ignore the server request and act as if an Expires value had been set.
This is a bit of a concern in shared user environments. If I set a authentication cookie that is set to expire at the end of the session. This will persist in Firefox after the browser has been closed and another user starts up Firefox. Cookies are set with an expiry date for a reason!
I'm flummoxed that Mozilla have left this as it is for several years.
OK.. so I quit FF and switch off the PC.
Next day FF starts and opens the last set of pages (nice handy feature) BUT it restores the sessions and I'm logged back in to sites which have no "save my settings" feature.
I know because they are sites I built.
Whatever I do with php ini settings the sessions are restored.
They absolutely should not be restored.
Pages yes, but sessions with cookie ini set to '0' no.
I don't understand why this is not flagged as a security hole.
Sure I can do some additional checking on the server side, to see if a login should be allowed, based on time from last log in, but it shouldn't be needed.
A session should NOT persist.
FF is manipulating cookie expiry settings.
In my case, it was because of pinned tabs that automatically restored the session even if this option was disabled in Firefox settings. So if you unpin the tabs, the session won't be restored.
Well it is disconcerting to me. My system is set up so that users can hit EXIT whereby I destroy all session cookies. But if a user closes the browser without actually choosing to Exit, I'd like the session cookies cleared.
I actually tested it with Google Chrome, IE 9, and works fine. But Firefox is reluctant to kill this "session" (as reported by Firebug) cookies.
OK. This is what I did. I chose Exit from FireFox main menu and from then on, did it fine as expected (Dont know why).
Related
This has been asked before, but I haven't seen anything posted about it in years, and I'm running into the problem now.
Steps to reproduce:
Log into my site (C# 6, angularjs, .Net Framework 4.8)
Once logged in, use Cookie Editor to export the session cookies in the browser (using Chrome in this instance, but that doesn't matter.)
Log out
Using Cookie editor, import the copied session cookies.
Refresh the page... voila - I'm logged back in.
So, my code for logging out does all the "get rid of stored cookies" things it should: loop through all the cookies and expire them; clear the Request.Cookies; Abandon the Session; Clear the Session; RemoveAll on the session.
But when you paste that dang .ASPXAUTH cookie back into the browser... whammo. Logged in.
I'm not sure how to prevent this, and could really use the help.
I have a very straightforward session system on my website: User logs in and the response on success contains a session token. The session token is then stored as a cookie with no expiry (expires=Fri, 31 Dec 9999 23:59:59 GMT) and root path (path=/).
On requests which require authentication, the client will send the session token value as part of the message, and as a fallback, also as a header and cookie.
Even so, from time to time I get users that just lose their sessions. Their session tokens are still valid, and they haven't logged out. All of a sudden, they apparently don't have the session cookie anymore. They were able to make requests for a while, and for many thousands of requests a day this happens maybe once every day or two so it's a rare occurrence. The requests don't seem to be malicious, they're just normal users who have the website open for a while and suddenly lose auth.
What are some things that can cause this (I expect in at least some cases it's some odd browser/OS setting out of my control)? What are some ways I can prevent this from happening without necessarily knowing the cause?
google Chrome, Firefox and other browsers plan to abandon cookies in near future source1, here is what you need to know. about GDPR and why so.
EU’s General Data Protection Regulation (GDPR) to let users from inside Europe control the activation of cookies and trackers that collect their personal data.
this could be a pain for companies eating cookies. because of the strict legal atmosphere for cookies these days.
a more robust Method to store persistent client side data is discussed here, you can even store whole databases via these methods discussed in MDN webpage. MDN=Mozilla developer Network.
Client-side storage: Link
Web Storage API : LINK
IndexedDB : Link
LocalStorage : LINK (next best alternative for cookies)
Highlights of LocalStorage API:
localStorage does the same thing, but persists even when the browser is closed and reopened. ie system reboot does not affect it.
Stores data with no expiration date, and
gets cleared only through JavaScript, or clearing the Browser cache / Locally Stored Data.
Storage limit is the non limiting around 5MB!
Are you perhaps redirecting domains? So for example: you SET the cookie ok productlogin.com and you redirect to product.com or any other server where you then want to READ the cookie? Because that won't work.
It could also be that your app is requesting the wrong cookie. Are you matching the same session? It could help us if you have some code to share.
What are the different ways of maintaining session in a browser?
Consider a scenario;
I am browsing a secure site in Firefox and the browser crashes. Now when I open the browser again and I do Restore tabs, my previous session is restored back ? Is that handled automatically by the browser OR is it code-based ?
Also can we control session based on tab close vs window close, etc
Is there any connect between maintaining the session at server vs having the same at client side?
What are the different ways of maintaining session in a browser?
Different ways to maintaining sessions are :-
Cookies ( Most Standard way )
Url Rewriting
Html Forms hidden fields
Consider a scenario; I am browsing a secure site in Firefox and the
browser crashes. Now when I open the browser again and I do Restore
tabs, my previous session is restored back ? Is that handled
automatically by the browser OR is it code-based ?
It is handled by browser automatically if it was cookie based, other wise you will manage that.
Also can we control session based on tab close vs window close, etc
On server you can control session just by time, mean when it will invalid, but if you want to do something that will invalid session when close tab then according to me you can bind on close event in javascript and then delete the cookie that was used to manage the session, PHPSESSION ( in php's case )
Is there any connect between maintaining the session at server vs
having the same at client side?
Yup :)
when you create a session actually you are sending a cookie.
Think you are coding in php, and you create a session, now what happens is: a file will be created on the server (file is the default way to handle session in php but you can also change that) and a unique id will also create on server that will represent that session, think you create a session so a file will created with name sjflsj3lrh324l2hjlskdjfl3hl.session and a unique id will also created ex:- sjflsj3lrh324l2hjlskdjfl3hl.
Now when you store anything in session you actually are storing that in this file, and when you will send response to browser, you will also send a cookie on browser and the cookie value will be this id. So next time when you reopen that web, browser will first check if there was any cookie received from this domain before. If yes, then send that with request, and then on server php will check if request contains any cookie with it. If so, then it will check if that name file exists, and if exists mean there was a session. It will then open that file and all variables values that was saved in it will be restored in php variables.
I am building a small web application and in my application I am using the session object to store information across calls to server. This works quite fine in Firefox \ Chrome\ IE, but it seems to fail in Safari. In Safari the session keeps forgetting that I've stored values in it.
Why is this happening? what can be done?
The session is based on an id stored in a cookie. The server uses this Id to link to your session on the server. It's highly likely cookies are off here. Load up fiddler or turn on tracing to see what cookies are being sent over... You should see the one with aspnetsessionid in it, if not your browser prob has them turned off.
You may also want to take a look over here: Facebook API and Safari
Looks like, if any redirect is sent when you are establishing cookies, they will be viewed as 3rd party cookies and could cause issues with your server-side.
if your settings on Safari are set to not allow cookies, then this fails. I have just had the same issue on an iphone web app im writing. I enabled cookies and all worked fine.
The whole idea of the Session is that the values are stored server-side. Safari can't possibly cause the server to forget something. Either the value wasn't ever stored in the Session or Safari is failing to render the Session value.
Trying using a debugger to confirm if the Session holds the correct value when passing the value into the Session and when you're attempting to retrieve the value from the Session.
Everything I read about cookies says that setting the expiry time of a cookie to zero should make it a `session' cookie, which the browser will then delete upon exit.
http://www.cookiecentral.com/faq/ says that :
"...generally a session is the length of time that the browser is open for..."
http://php.net/manual/en/function.setcookie.php says :
"If set to 0, or omitted, the cookie will expire at the end of the session (when the browser closes)."
However, some experimenting in Firefox (3.0.8) shows that:
cookies set as session and secure get deleted on exit
cookies set as session only do not get deleted on exit
Opera (9.64) behaves as I would expect, deleting the session cookies upon exit whether set as secure or not.
I wanted to be able to rely on this in a web-app I'm working on (having a secure cookie and an insecure cookie as a "logged-in" flag and having them expire together, either with a real time or 0 for a session), but it seems that even if it's in the standard then browsers are not consistent enough to rely on it :/
Is this a bug in the browser, expected behaviour, and/or is the actual lifetime of session cookies not really defined in the standard?
You should never rely on client-side features.
The feature you're working on is usually implemented storing the session ID client-side and the real user info server-side (its ID, whether he's logged in or not, his personal info, etc).
Also bear in mind cookies get sent in every request, so the less you store in a cookie, the better.