Why I Started Hacking Google Wave

After I posted concerns over security in Google Wave, several responses came (including one from Google) emphasizing that Wave was “still in an early preview stage” and many bugs would be fixed before a wider release. I think that clarifying why I would bother discussing bugs in a preview product may raise a few important points about web application security.

First, let me be clear about one point: I would not pretend to know more about application security than the engineers, programmers, and scientists at Google. In addition, I would not want to imply that Google does not care about security or user privacy. I realize that Google takes security issues seriously and has the resources to build highly secure products.

But those realizations are also a source of confusion for me when I observe decisions made about Google Wave. As an outsider, I don’t understand why Wave would include the problems I’ve outlined. What I’ve posted does not involve clever hacks or specific parameters – these problems involve weaknesses in the overall framework of Wave. And such weaknesses relate to well-known issues in application security. In fact, Google has previously addressed deploying third-party code by developing Caja after the launch of OpenSocial.

Returning to the “it’s a preview” argument, though, I would first respond by saying that applications, particularly ones that allow users to embed untrusted third-party code, should include security from the very beginning. Starting with an open model and trying to add restrictions later on is a recipe for disaster.

A larger issue in Wave’s case, though, is that Google has often cast Wave as a reinvention of SMTP e-mail. If you set expectations high, much will be expected of you. If a company with the reputation, resources, and revenue of Google markets a product as a replacement for traditional e-mail, I’m going to evaluate its security even more closely than normal. In my view, the hype that has already built around Wave and the reach it’s already found (Novell is reportedly planning a Wave-based business product in mid-2010) disallow the “preview” excuse.

In addition, if you’re going to reinvent e-mail, don’t forget lessons already learned from traditional e-mail. In a previous post, I outlined four major weaknesses I saw in Google Wave:

1. Allowing scripts and iframes in gadgets with no limits apart from sandboxing
2. Lack of control over what content or users can be added to a wave
3. No simple mechanism for verifying gadget sources or features
4. Automatically loading gadgets when a wave is viewed

Name one webmail interface that executes scripts in messages. Name one recent e-mail client that automatically loads content such as images in messages. Why were such considerations not part of Wave from the very start?

Of course, while Google has at least promised to include further permissions controls in Wave, such controls are one aspect of Wave intentionally left out in initial releases. While one can argue whether Google is correct in the merits of such collaboration, I’m a bit surprised that more of the security implications have not been raised before (at least not to my knowledge). When such changes will appear, though, remains to be seen. Personally, I find it a tad disconcerting that Google has similarly promised such updates as allowing users to turn off Wave’s real-time typing behavior, yet Wave has changed little since its announcement.

Still, I’m confident that Google will address at least some of the issues I’ve raised. If nothing else, I hope I’ve contributed to the public dialogue about Google Wave. I will add that Wave appears to include much security on the backend – most of the problems I’m seeing come in the client implementation. Let’s remember, though, that Wave will be federated. Another reason to bring up client security issues early is that other clients can learn from Google’s implementation. I’m rather concerned that if Wave interfaces proliferate, they may repeat many of the security problems seen in early e-mail interfaces.

I’m also concerned that Wave is not really addressing many of the issues that have plagued e-mail. The current “chaos” with Wave’s lack of permissions does not bode well for how it will handle spam, for instance. Whitelisting alone won’t do the trick. In fact, I would argue that Wave is a collaboration tool, not a communication tool, and thus not a replacement for e-mail.

In conclusion, I’d simply add one more point. While it’s exciting to find exploits such as specific XSS holes on a web site, it’s often more important to raise awareness regarding larger security issues that relate to the overall framework of an application. That’s why I’ve discussed FAXX hacks so much, as they relate to the overall implementation of the Facebook Platform instead of particular vulnerabilities.

Similarly, my concerns about Google Wave thus far involve behaviors built into the current system that open the door for exploiting the privacy and security of users. Preview or not, Wave needs to address these high-level weaknesses if it’s going to match the hype.