Category: Coding

NOTE: This is the first of two posts looking at problems I see with Pressgram. The second, addressing the Terms of Service can be read here.

Hi, folks. Gather round, and let’s have a little chat about password security and transparency.

So Pressgram just released, after a rather successful Kickstarter campaign, and lots of excitement by the community. Hurrah, congratulations, folks! Getting a public release actually shipped is the toughest part of any project, and you’ve got that out. Well done!

I installed the app last night, kicked the tires, and examined how it operates a bit, and I’ve got some concerns that I’d like to voice.

First, though, a bit of background. On the official WordPress Mobile Apps, there’s only so much security that can be reasonably achieved via the XML-RPC API that they (and pretty much all apps) use. With XML-RPC, there are no authentication tokens, you need to send your password in plaintext. Which is normally totally fine, as the password is just stored by your local phone (the security of which you are responsible for yourself), and then stored in a double-hashed and salted form on the server.

It seems that, unlike the WordPress Mobile Apps, the password that you enter in Pressgram isn’t kept private on your own device. Without noting it on a Privacy Policy or in any way notifying you that Pressgram is doing it, your password is stored in plaintext on their server. Which — to be fair — is necessary, if they’re going to be pushing data from the Pressgram Server to your WordPress site, and not going to require having a specialized plugin (like Jetpack) installed on your WordPress site to do it. And I don’t think that Jetpack is necessarily a worthwhile dependency to have for an app like this.

My first concern is that I don’t really like my passwords being stored in plaintext on a third-party server that could be hacked (or for that matter, required to be turned over by an order from a FISA court). Some other applications, such as IFTTT do the same thing, but at least with them, it’s transparent that it’s going to be their server holding your credentials and accessing your WordPress site.

With Pressgram, without further investigation, one would believe that it’s the app directly uploading the files to your WordPress site. After all, that’s what the Kickstarter initially pledged:

I suppose another way you could say it is… it’s your filtered photos published directly to your WordPress-powered blog, when you want, where you want, how you want.

But that’s not the case! For the curious, here’s what I saw when running a test against a honeypot standalone site where I was trapping all the requests sent to it:

Firstly, the App sends two requests to /xmlrpc.php

XXX.XX.XXX.XXX - - [06/Sep/2013:02:51:51 +0000] "POST /xmlrpc.php HTTP/1.1" 200 904 "-" "John.Saddington.Pressgram/1.0 (unknown, iPhone OS 6.1.4, iPhone, Scale/2.000000)"
[Fri Sep 06 02:51:51 2013] [error] [client 174.59.108.165] <?xml version="1.0"?><methodCall><methodName>system.listMethods</methodName><params></params></methodCall>
XXX.XX.XXX.XXX - - [06/Sep/2013:02:51:52 +0000] "POST /xmlrpc.php HTTP/1.1" 200 512 "-" "John.Saddington.Pressgram/1.0 (unknown, iPhone OS 6.1.4, iPhone, Scale/2.000000)"
[Fri Sep 06 02:51:52 2013] [error] [client 174.59.108.165] <?xml version="1.0"?><methodCall><methodName>wp.getUsersBlogs</methodName><params><param><value><string>admin</string></value></param><param><value><string>password</string></value></param></params></methodCall>

These two requests firstly make sure that the site is there and is a WordPress install, and secondly makes sure that the credentials work — and if it’s a multisite install, returns the available blogs.

So far, so good. The User Agent strings are clear as to what they are and what they’re accomplishing.

Then, ten requests come in:

YY.YYY.YYY.YYY - - [06/Sep/2013:02:53:27 +0000] "POST /xmlrpc.php HTTP/1.1" 200 1845 "-" "-"
[Fri Sep 06 02:53:27 2013] [error] [client YY.YYY.YYY.YYY] <?xml version="1.0" encoding="iso-8859-1"?>
<methodCall>
<methodName>wp.getTerms</methodName>
<params>
<param>
<value>
<int>1</int>
</value>
</param>
<param>
<value>
<string>admin</string>
</value>
</param>
<param>
<value>
<string>password</string>
</value>
</param>
<param>
<value>
<string>category</string>
</value>
</param>
<param>
<value>
<array>
<data/>
</array>
</value>
</param>
</params>
</methodCall>

and nine others very much like it. If anyone is curious to see them, tweet me, and I’ll post them for folks to review. Checking existing taxonomies, creating new terms, uploading the photo, and creating the post.

XXX.XX.XXX.XXX is the IP address of my phone. YY.YYY.YYY.YYY is the IP Address of the Amazon Cloud Server that Pressgram works off of. I’ve anonymized these just for the sake of privacy. They’re easy enough to find, but it’s not my business to release them. I’ve also removed the base64 encoded image data.

I’ve also captured the request that the Pressgram App uses to send your password up to the Pressgram server — it looks something like this:

URL: https://api.pressgr.am/index.php/Api/postPhotoData
Data:
{
	"social": {},
	"post_content": "Pic",
	"sessionId": "00000000000000000000000000000000",
	"blog": [{
		"title": "Pic",
		"password": "password",
		"login": "admin",
		"url": "honeypot.example.com"
	}],
	"identifier_photo": "0000000000.0000000000"
}

So at least it’s being sent to the Pressgram server over HTTPS.

You’ll notice that the requests coming from the Pressgram Server have no User Agent to identify what they’re there for. They’re all signed with username and password — meaning that the Pressgram servers now have my username and password in plaintext, with not even a notification to me in their Privacy Policy or Terms of Service that this is being transferred up to their servers.

So what does this all mean?

Well, it means that Pressgram is storing your credentials in plaintext (or potentially encrypted alongside a decryption key) on your behalf, without notifying you or doing anything publicly to indicate that this is the case. No matter how high entropy your passwords may be, if you hand it to someone and they get hacked, it doesn’t matter. You are vulnerable — doubly so if you use that password for other accounts as well.

To some folks, this may be a worthwhile tradeoff. But as I look at it, I don’t see it as a necessary tradeoff. Your credentials could just as easily be kept private between the app on your phone, and your WordPress site. Just have your phone upload the photo directly to your WordPress install. It wouldn’t be difficult to do, it’s already making XMLRPC requests to the server. And it fulfills the initial Kickstarter promise of “your filtered photos published directly to your WordPress-powered blog”. It also would provide the added security that if Pressgram is eventually shut down or sold off, the app would still function, as it’s not needlessly dependent on the Pressgram Servers.

To protect yourself, you may want to consider making a seperate account for your WordPress site with the Author role, and using those credentials with Pressgram, and make sure you’re using a distinct password — as well as with any service that you provide a password to.

Conclusion

So in the end, what am I calling for?

Ideally, I’d like to see Pressgram give users the option of simply taking photos, and uploading them directly from the app to their WordPress blog. No servers in the middle with potential vulnerabilities for your data. In short — make the account creation and login optional. Give folks a choice! That sounds a lot more like what the Kickstarter was proposing. If you’d like to build a new social network on top of it (if I had a dime every time a potential client tried building that), make it optional!

Do I see that happening? Well, I hope so, but I’ve found that companies don’t normally like to make themselves less integral to a process. So at the very least, notify your users that their credentials are going to be stored on your servers. To take them as Pressgram has without any such public warning I see as morally questionable, and totally contrary to the values of the WordPress community, which embraces transparency, and not forcing unnecessary service dependencies between you and your site.

—

UPDATE: Pressgram has updated their Terms of Service to indicate that your content may travel through their network to get to your blog.  Unfortunately, it says nothing in the TOS or its Privacy Policy about your username and password being stored on or passing through its servers.