How Pwn2Own Was Almost Won Via XSS | Hacker News Reader

How Pwn2Own Was Almost Won Via XSS

jon.oberheide.org

64 pointsssclafani14 comments

Dear Google,

While I am impressed with the ease and speed the web market can install an application on my phone (it seems to trigger basically instantaneously), I was very dismayed at the security implications of this functionality. This example is only one of a myriad of reasons I'd rather not have it enabled.

Please allow me to disable this functionality on the device itself (and not just as an option accessible to my account on the web).

I met Jon a few weeks ago and we talked about the possibility of this exploit. At the time I didn't believe that the folks at Google would miss something like this.

It just goes to show you can't be too careful when interacting with today's cloud services.

I'm not sure this implicates cloud in particular.

I see it as a company that doesn't understand the difference between securing an operating system and securing a website. Which is especially bad considering the train wreck that is web security. Jon was apologetic that his bug was so 'lame' since, unlike operating systems, the web was generally not designed to be secure.

"Web security" in general depends on the secure behavior of the web browser, which in turn depends on the security of the operating system, hardware, and so on. If you reverse the arrows in the architecture, as Android appears to have done with Marketplace, then the whole thing becomes much less stable.

Yes of course not cloud in particular, but web services in general. It just gave me pause because if Google messed this up, how many other services with less man power that we trust with our data have similar vulnerabilities?

Approximately all of them.

IMHO, browsers' implementation of the web "security model" (I use the term loosely) is not the thing to base the security of your entire architecture on.

But hey, who am I to argue with Google?

Am I reading this right that there is absolutely no HTML escaping for app descriptions on the Android Market? Seriously Google, like none?

Was. It's fixed now, apparently ;)

Someone at Google probably got in trouble over this.

Remember when YouTube had a similar issue with <script> tags executing from within comments?

It wasn't quite that simple ;-)

http://www.reddit.com/r/programming/comments/cluc5/html_inje...

The payload in the case of YouTube was only slightly more complex (two <script> tags instead of one), but it sounds like the underlying cause was very different.

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Many websites and web applications are vulnerable to XSS in one form or another. The difference here, as people have pointed out, is the trust placed in the site by Android. It's not very often that an XSS vulnerability can execute arbitrary code on a remote system. :-P

I think the underlying cause was the same - unescaped output that was supplied by the (malicious) user.

Mmm, from here it looks like YouTube had a sanitizer in place that failed: it's not clear that the Android Market was sanitizing the output here. That's what I meant by the underlying cause being different.

> Unfortunately, Google had significantly tightened things up and we’ve been unable to expose any additional XSS

I'm impressed that not only did Google fixing the vulnerability but they also appears to have done a full security audit. To many companies would just fix the known hole and leave it at that.

This made my day. You'll often hear people exclaim that XSS vulnerabilities don't matter because they're all client-side, but they are a means to an end. They are but the tip of the iceberg; without the tip, the rest of the iceberg is invisible.

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