Proxy caches, combined with poorly written session management code, can easily leads to serious security flaws similar to what we highlighted in A New Security Breach in Google Docs Revealed.

Web developers have no control over proxy caches in the Internet. However, developers do have control of the code they write and their admin teams have configuration control of their web servers. Developers must assume the worst case Internet scenario with aggressive Internet cache management policies that serve cached data for economic and performance reasons.

As a consequence, this fact-of-life on the Internet sometimes results in multiple web clients being sent the same Set-Cookie HTTP headers, for example.  Caching proxy servers should obtain a fresh cookie for the each new client request. Ideally, proxy caches should not cache session management cookies and distribute cached cookies to multiple clients. However, application developers cannot assume that proxy caches are well behaved, especially for applications where security and privacy are required.

Web developers cannot know whether their content is consumed directly or via a proxy cache. Developers also cannot assume that the HTTP responses will be delivered to the intended browser. Moreover, developers cannot be sure that the intended browser even receives the intended content.  For example, a session ID issued to a client gets used while it is valid or until abandoned and expired. If it is served and delivered in response to an unencrypted HTTP GET request, there’s no guarantee it will be consumed by the intended web browser.

Ideally, SSL should be used on all web transactions that require confidentiality and privacy, including our recent Google Docs breach.  On the other hand, even SSL is not foolproof. For example, many web developers do not correctly set the “Encrypted Sessions Only” cookie property. These incorrectly configured “secure” servers will send HTTPS cookies in the open, unencrypted.

There be dragons …

• All my presentation on Slideshare.
  

I’m sure you already know about the other “network management” – where ISPs and carriers get their hands publicly slapped for limiting bandwidth to high-traffic offenders. But when is this kind of “network management” a good thing? At a panel sponsored by the FCC in DC, reps from carriers and ISPs discussed what steps they’ve been taking to prepare for a pandemic or other major global crisis – that would force workers to stay at home or work from more remote locations to limit exposure.

Are people paying attention to ICANN? They’re saying that IPv4 will be fully allocated in the next two or three years. Does anyone care? In their bid to make people care, ICANN talks about the state of IPv6 adoption and touts Africa as the most rapid adopter.

SOA soon part of the ‘cloud’? No, please no.

Microsoft – The Silver Lining in Every Cloud. Joe Wilcox over at eWeek’s Microsoft Watch, has been following Steve Ballmer around and collecting some nice quotes on how the company is transitioning. “For many years, we had kind of what I would call the all-encompassing mission, vision and scorecard statement: a computer on every desk and in every home. …Well, our footprint and portfolio is broader than that. “ [In every hand and of course, in every cloud…] “So, as a vision statement we talk about creating seamless experiences that combine the magic of software, the power of the Internet across a world of devices.” The magic of software – something I haven’t thought about for a while. And:

“You need a real platform in the cloud. When we wanted to go after the PC, we built an operating system. When we wanted to go after the phone, we built an operating system. When we wanted to go after the enterprise, we built an operating system. We’ll announce a new operating system, one that runs in the cloud and has a wide variety of capabilities.”