In Outlook Live browser cookie issues, I discussed the issues surrounding cookie usage and the Outlook Live service. As you may remember, one of the problems surrounding turning off the blind support of third-party cookies is the check that is performed at logout. If the check doesn’t pass then you will get a warning message.
The fix for this from the MS perspective is to enable third-party cookies. One of the main reasons to not follow this is for better privacy while browsing the Internet. As with most computer security, web browser security is often a trade-off between usability and security. You have to know what to set things to to achieve a balance between good security and acceptable annoyance. Many users install ad-blockers, flash blockers, disable Javascript, etc. These are good tactics, but they also introduce browsing annoyances since the very technologies these plug-ins disable are what makes the web experience interesting and fun. For more on browser security check out Securing Your Web Browser at CERT.
Fortunately, in this particular case the solution is relatively easy. Since Mozilla gives us the ability to configure the browser directly, we can change how Firefox handles cookies.
First you will need to open Firefox and go to the site about:config to edit the settings. This is not really a website, but a method provided to directly configure some browser settings. You will be presented with a warning box, just click the button.
Next, in the filter box type network.cookie, this will narrow the list displayed down to only the ones dealing with cookies. One of the settings to be changed already exists, the other will have to be added.
The setting that you want to change is:
- network.cookie.cookieBehavior
Change network.cookie.cookieBehavior to have a setting of 3, enabling the change, by double clicking on the number in the Value column and entering the new value in the dialog box.
To add the new preference, right click in the window and select Integer from the New submenu.
Enter network.cookie.p3plevel in the dialog box that appears. Set the value to be 3 in the second dialog box. There is no save function, the changes take effect immediately, just close you browser tab/window.
After making these changes you will now be able to successfully navigate the Outlook Live site and logout without getting the warning message. You will also be better protected from nefarious third-party cookies.
If you want to change the preferences back to the defaults, simply open the preferences for Firefox and click the checkbox next to Accept third-party cookies.
Apparently this functionality was part of Firefox 2 but was subsequently removed after someone complained about the size of the code required to implement it (a total of 60k in what is now a 56.9MB, at least that’s the size of the application on Mac OS X). In reading through the comments in the Bugzilla post, I fail to see where anyone makes a decent argument for reducing end-user security. For more on all of this, check out the references section of this post.
These changes were implemented on Mac OS X 10.6.4 using Firefox 3.6.11, but it should be pertinent to Windows and Linux as well.
References
In June of 2010, Valdosta State University transitioned to using Microsoft’s Live@EDU service for our e-mail. This is Microsoft’s competing product line with Google’s Apps for Education service. There were many reasons why we chose the Microsoft service which I won’t get into here, suffice it to say, that was the decision that was made.
While I don’t use the web interface all that much, when I do use it on Safari 5 for the Mac, I have noticed an oddity. After you login to the system and do whatever you plan to do that session, to logout you should click the “Sign Out” link. Seems standard enough, right? Well, not exactly. On Safari on the Mac I have noticed that I get an error when the signout process is attempted. When testing Firefox 3.6.11, I found I wasn’t receiving the error screen and the signout process completed successfully.
After delving more into this it turns out that the problem is third-party cookies. The default settings in Safari are very restrictive. They are also all or none. There is no exception list to the privacy settings for browser cookies in Safari, unlike Firefox. Also, it turns out that if you change the settings in Firefox to match the restrictive settings in Safari you get the same error screen.
In order to find out what site was causing the problem I cleared all the cookies for Safari, then enable the setting to always allow cookies. After comparing the list of cookies that were set, I found one listed for the domain passport.com that did not show up in the cookie list when Safari is set to accept cookies only from sites that I visited.
Further investigation using the Live HTTP Headers add-on in Firefox revealed the following for that domain:
http://loginnet.passport.com/ThirdPartyCookieCheck.srf?ct=1287943985 GET /ThirdPartyCookieCheck.srf?ct=1287943985 HTTP/1.1 Host: loginnet.passport.com User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.11) Gecko/20101012 Firefox/3.6.11 Accept: image/png,image/*;q=0.8,*/*;q=0.5 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 115 Connection: keep-alive Referer: http://login.live.com/logout.srf?lc=1033&nossl=1&lc=1033&ru=https://login.microsoftonline.com/login.srf%3Flc%3D1033%26ct%3D1287943985%26rver%3D6.1.6206.0%26id%3D260563%26wa%3Dwsignoutcleanup1.0%26nossl%3D1%26wreply%3Dhttps:%252F%252Foutlook.com%252Fowa%252F%253Frealm%253Dvaldosta.edu&id=12&wa=wsignout1.0 HTTP/1.1 302 Found Connection: close Date: Sun, 24 Oct 2010 18:13:05 GMT Server: Microsoft-IIS/6.0 PPServer: PPV: 30 H: BAYIDSLGN1F57 V: 0 Content-Type: text/html; charset=utf-8 Expires: Sun, 24 Oct 2010 18:12:05 GMT Cache-Control: no-cache Pragma: no-cache P3P: CP="DSP CUR OTPi IND OTRi ONL FIN" Set-Cookie: MSPP3RD=2832116359; domain=.passport.com;path=/;HTTPOnly= ;version=1 Content-Length: 0 Location: http://loginnet.passport.com/ThirdPartyCookieCheck.srf?tpc=2832116359&lc=1033 ---------------------------------------------------------- http://loginnet.passport.com/ThirdPartyCookieCheck.srf?tpc=2832116359&lc=1033 GET /ThirdPartyCookieCheck.srf?tpc=2832116359&lc=1033 HTTP/1.1 Host: loginnet.passport.com User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.11) Gecko/20101012 Firefox/3.6.11 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en-us,en;q=0.5 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 115 Connection: keep-alive Referer: http://login.live.com/logout.srf?lc=1033&nossl=1&lc=1033&ru=https://login.microsoftonline.com/login.srf%3Flc%3D1033%26ct%3D1287943985%26rver%3D6.1.6206.0%26id%3D260563%26wa%3Dwsignoutcleanup1.0%26nossl%3D1%26wreply%3Dhttps:%252F%252Foutlook.com%252Fowa%252F%253Frealm%253Dvaldosta.edu&id=12&wa=wsignout1.0 Cookie: MSPP3RD=2832116359 HTTP/1.1 200 OK Cache-Control: no-cache Connection: close Date: Sun, 24 Oct 2010 18:13:06 GMT Pragma: no-cache Content-Type: image/gif Expires: Sun, 24 Oct 2010 18:12:06 GMT Server: Microsoft-IIS/6.0 PPServer: PPV: 30 H: BAYIDSLGN1F50 V: 0 P3P: CP="DSP CUR OTPi IND OTRi ONL FIN" Content-Encoding: gzip Vary: Accept-Encoding Transfer-Encoding: chunked
Continuing the investigation, I decided to force Firefox to ask me about each cookie that was going to be set. This makes a dialog show up for each cookie attempt giving me the option to deny it, allow it only for the current session, or always allow. After walking through the tortorous process of a complete login/logout session, it turns out that two cookies are being set for the domain passport.com with each of them set to expire at the end of the session. More detail on the cookie can be seen in the screen shot of the cookie detail (provided by the plugin Add N Edit Cookies) shown below:
So, the next step was to fire up my VM and see how all this worked on the Windows side of things. I figured that since we had not been deluged with user requests concerning this that the browsers on the Windows side of the equation were handling it all differently. Firefox on Windows is configured out of the box just like Firefox on Mac OS X. So, as I expected the operation was the same as well. If you allow for third-party cookies, then it works fine, if you don’t then you get the error screen.
The interesting development is the settings for Internet Explorer. Bear in mind that I am using Windows 7 and Internet Explorer 8, but the settings should be fairly similar on Windows XP and between versions 7 and 8. The default setting in IE8 is to all third-party cookies, but (and this is the key) only if they have a compact privacy policy (P3P). This is the setting that makes the big difference.
It turns out that neither Firefox nor Safari support P3P headers by default. In fact there doesn’t appear to be any support for them in Safari at all. Configuring Firefox to support them requires some advanced editing of the main configuration file.
I haven’t found any adverse effects to the workings of Outlook Live when using Safari, but it is rather annoying that this occurs.