WebApp Sec mailing list archives
Re: concurrent logins
From: Robin Wood <robin@digi.ninja>
Date: Fri, 21 Nov 2014 12:23:10 +0000
On 19 November 2014 14:27, Aaron Sanders <malmoose37 () gmail com> wrote:
Just thinking out loud (still haven't had coffee yet) but what about second factor? Is that in scope for this question? I would think you can allow all the concurrent sessions a user wants as long as all of them were validated with second factor. If an adversary can compromise the second factor source then there are bigger issues. Though I suppose a session hijack is still possible after the dual auth. To cover that case, what about source ip tracking? Session tokens don't normally travel across systems so if the ip changes then user needs to re-auth.
The reason I was thinking about this is the thing I was reading was suggesting to prevent session hijacking that concurrent logins should not be allowed, 2FA stops actual logins but not hijacks. Tying sessions to source IP can be a problem when users are on networks that can switch egress IP. Robin
-Aaron On Nov 19, 2014 7:00 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 This list is sponsored by Cenzic -------------------------------------- Let Us Hack You. Before Hackers Do! It's Finally Here - The Cenzic Website HealthCheck. FREE. Request Yours Now! http://www.cenzic.com/2009HClaunch_Securityfocus --------------------------------------
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Current thread:
- Re: concurrent logins, (continued)
- Re: concurrent logins DavidMeans833 () air-watch com (Nov 19)
- Message not available
- Re: concurrent logins Robin Wood (Nov 19)
- Message not available
- Re: concurrent logins Robin Wood (Nov 21)
- Re: concurrent logins Robin Wood (Nov 19)
- Re: concurrent logins Arvind (Nov 19)
- Re: concurrent logins Seth Art (Nov 19)
- Re: concurrent logins Matt Konda (Nov 19)
- Re: concurrent logins James Wright (Nov 19)
- RE: concurrent logins Zaakiy Siddiqui (Nov 19)
- Message not available
- Re: concurrent logins Robin Wood (Nov 21)
- Message not available
- Re: concurrent logins Robin Wood (Nov 21)
- Message not available
- Re: concurrent logins Robin Wood (Nov 21)
- RE: concurrent logins Martin O'Neal (Nov 19)
- Re: concurrent logins Robin Wood (Nov 19)
- Re: concurrent logins Stephen de Vries (Nov 24)
- Re: concurrent logins Robin Wood (Nov 24)