RE: Is logoff feature necessary

["Popowycz, Alex" <Alex.Popowycz () fmr com>]

It depends on the session state mechanism used and whether it's server
or browser side (e.g. cookies). But in any event, having a logout
ensures a cleaner / complete logout.  Say the user has multiple browser
windows open in a given instance.  They may (errantly) conclude that
closing the window of the site they wish to log out of will actually log
them out when it won't.  Also, for sessions managed by the host (e.g.
session keys, etc) closing out the browser, even completely, still
leaves the opening of a replay attack out of the browser cache (if the
session variables are carried as query string parameters) which can be
common in shared used environments like kiosks, library computers, etc.

-----Original Message-----
From: test.future () gmail com [mailto:test.future () gmail com] 
Sent: Tuesday, May 02, 2006 3:41 AM
To: webappsec () securityfocus com
Subject: Is logoff feature necessary


We have a web applicaiton which do not have logoff button. The developer
claims that it is unnecessary, since the session can be terminated by
closing the browser. Is it correct? Thanks.

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