Re: concurrent logins

[James Wright <jamfwright () gmail com>]

Hi Robin,

As you said, it depends a lot on what the application is for.  If it
is something like email, a user may wish to access it on a computer
and a smartphone, and stay logged into both.

If the web based system requires more security, or is limited by a
license (100 concurrent user limit) or another resource limit, it may
be useful to limit concurrent logins.  My thought on this is that the
application should allow the logging on user to choose whether or not
to disconnect the already existing connection.  This way users can
force off old and stale connections (reduced support from IT or
AppDevs), and is alarming to the user if an attacker forces someone
off (user will most likely report the occurrence).

With concurrent users, very few monitor or care about sessions other
than the one they are currently using.  Not allowing a user to login
because of another running session is a headache for the user, and
creates more support tickets.


Thanks,
James

On Wed, Nov 19, 2014 at 5:30 AM, Robin Wood <robin@digi.ninja> wrote:
> What are peoples opinions on allowing concurrent logins to web apps? I
> suppose it depends on what the app is used for - forum, admin suite
> etc - but do the protections from it add more problems that allowing
> it?
>
> Solutions I can see are:
>
> 1. Allow concurrent logins
> 2. Allow concurrent logins but report that someone else is logged it -
> like Gmail does
> 3. Don't allow them and kick out any logged in user when a new one logs in
> 4. Don't allow them and lock out all new logins till old ones have logged out
> 5. Give a warning popup when logging in to say the account is in use
> elsewhere as well
> 6. Allow but report back to an admin or log tracker or similar
>
> 1 is the default in most cases.
> 2 is a good idea but really, how many people look at the little thing
> in Gmail which says where else the account is logged in from, I don't
> and I'm sure normal users don't even know it exists.
> 3. Good but if an attacker gets creds or a reliable session hijack
> then they can use them to DoS legit users by keep logging them out.
> 4. Good but if an attacker gets in they can keep the account active
> and so DoS the real user by never letting them log in.
> 5. Maybe the best option but only works in the legit user logs in
> second otherwise the attacker gets the warning and ignores it.
> 6. Good one if people are watching the logs and can act on them.
>
> What other options are there? Can it be done in a good way that makes
> if of any use?
>
> Robin
>
>
>
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