Yik Yak MITM Hack (Give the Dog a Bone)

Yik Yak is growing in popularity lately. If you are unfamiliar with Yik Yak, here’s the run down. It’s kind of like Twitter, but your messages are only shared with people who are currently within a few miles of you. Also, your account is supposed to be totally anonymous. When you combine anonymity and location, you get some interesting results. The app seems to be most popular in schools. The anonymity allows users to post their honest thoughts without fear of scrutiny.

[Sanford Moskowitz] decided to do some digging into Yik Yak’s authentication system. He wanted to see just how secure this “anonymous” app really is. As it turns out, not as much as one would hope. The primary vulnerability is that Yik Yak authenticates users based solely on a user ID. There are no passwords. If you know the user’s ID number, it’s game over.

The first thing [Sanford] looked for was an encrypted connection to try to sniff out User ID’s. It turned out that Yik Yak does actually encrypt the connection to its own servers, at least for the iPhone app. Not to worry, mobile apps always connect to other services for things like ad networks, user tracking, etc. Yik Yak happens to make a call to an analytics tool called Flurry every time the app is fired. Flurry needs a way to track the users for Yik Yak, so of course the Yik Yak App tells Flurry the user’s ID. What other information would the anonymous app have to send?

Unfortunately, Flurry disables HTTPS by default, so this initial communication is in plain text. That means that even though Yik Yak’s own communications are protected, the User ID is still exposed and vulnerable. [Sanford] has published a shell script to make it easy to sniff out these user ID’s if you are on the same network as the user.

Once you have the user ID, you can take complete control over the account. [Sanford] has also published scripts to make this part simple. The scripts will allow you to print out every single message a user has posted. He also describes a method to alter the Yik Yak installation on a rooted iPhone so that the app runs under the victim’s user ID. This gives you full access as if you owned the account yourself.

Oh, there’s another problem too. The Android app is programmed to ignore bad SSL certificates. This means that any script kiddie can perform a simple man in the middle attack with a fake SSL certificate and the app will still function. It doesn’t even throw a warning to the user. This just allows for another method to steal a user ID.

So now you have control over some poor user’s account but at least they are still anonymous, right? That depends. The Yik Yak app itself appears to keep anonymity, but by analyzing the traffic coming from the client IP address can make it trivial to identify a person. First of all, [Sanford] mentions that a host name can be a dead giveaway. A host named “Joe’s iPhone” might be a pretty big clue. Other than that, looking out for user names and information from other unencrypted sites is easy enough, and that would likely give you everything you need to identify someone. Keep this in mind the next time you post something “anonymously” to the Internet.

[via Reddit]

Bad Code Results in Useless Passwords

[HeadlessZeke] was excited to try out his new AT&T wireless cable box, but was quickly dismayed by the required wireless access point that came bundled with it. Apparently in order to use the cable box, you also need to have this access point enabled. Not one to blindly put unknown devices on his network, [HeadlessZeke] did some investigating.

The wireless access point was an Arris VAP2500. At first glance, things seemed pretty good. It used WPA2 encryption with a long and seemingly random key. Some more digging revealed a host of security problems, however.

It didn’t take long for [HeadlessZeke] to find the web administration portal. Of course, it required authentication and he didn’t know the credentials. [HeadlessZeke] tried connecting to as many pages as he could, but they all required user authentication. All but one. There existed a plain text file in the root of the web server called “admin.conf”. It contained a list of usernames and hashed passwords. That was strike one for this device.

[HeadlessZeke] could have attempted to crack the passwords but he decided to go further down this rabbit hole instead. He pulled the source code out of the firmware and looked at the authentication mechanism. The system checks the username and password and then sets a cookie to let the system know the user is authenticated. It sounds fine, but upon further inspection it turned out that the data in the cookie was simply an MD5 hash of the username. This may not sound bad, but it means that all you have to do to authenticate is manually create your own cookie with the MD5 hash of any user you want to use. The system will see that cookie and assume you’ve authenticated. You don’t even have to have the password! Strike two.

Now that [HeadlessZeke] was logged into the administration site, he was able to gain access to more functions. One page actually allows the user to select a command from a drop down box and then apply a text argument to go with that command. The command is then run in the device’s shell. It turned out the text arguments were not sanitized at all. This meant that [HeadlessZeke] could append extra commands to the initial command and run any shell command he wanted. That’s strike three. Three strikes and you’re out!

[HeadlessZeke] reported these vulnerabilities to Arris and they have now been patched in the latest firmware version. Something tells us there are likely many more vulnerabilities in this device, though.

[via Reddit]

SpoofedMe Attack Steals Accounts by Exploiting Social Login Mechanisms

We’ve all seen the social logon pop up boxes. You try to log into some website only to be presented with that pop up box that says, “Log in with Facebook/Twitter/Google”. It’s a nice idea in theory. You can log into many websites by using just one credential. It sounds convenient, but IBM X-Force researchers have recently shown how this can be bad for the security of your accounts. And what’s worse is you are more vulnerable if the service is offered and you are NOT using it. The researcher’s have called their new exploit SpoofedMe. It’s aptly named, considering it allows an attacker to spoof a user of a vulnerable website and log in under that user’s account.

So how does it work? The exploit relies on vulnerabilities in both the identity provider (Facebook/Twitter/etc) and the “relying website”. The relying website is whatever website the user is trying to log into using their social media account. The easiest way to describe the vulnerability is to walk through an example. Here we go.

Let’s imagine you are an attacker and you want to get into some victim’s Slashdot account. Slashdot allows you to create a local account within their system if you like, or you can log in using your LinkedIn account. Your victim doesn’t actually have a LinkedIn account, they use a local Slashdot account.

The first step of your attack would be to create a LinkedIn account using your victim’s email address. This needs to be the same address the victim is using for their local Slashdot account. This is where the first vulnerability comes in. LinkedIn needs to allow the creation of the account without verifying that the email address belongs to you.

The second step of the attack is now to attempt to log into Slashdot using your newly created LinkedIn account. This is where the second vulnerability comes in. Some social media services will authenticate you to websites like Slashdot by sending Slashdot your user information. In this case, the key piece of information is your email address. Here’s the third vulnerability. Slashdot sees that your LinkedIn account has the same email address as one of their local users. Slashdot assumes that LinkedIn has verified the account and permits you, the attacker, to log in as that user. You now have access to your victim’s Slashdot account. In another scenario, Slashdot might actually merge the two credentials together into one account.

What’s really interesting about this hack is that it isn’t even very technical. Anyone can do this. All you need is the victim’s email address and you can try this on various social media sites to see if it works. It’s even more interesting that you are actually more vulnerable if you are not using the social logons. Some real world examples of this vulnerability are with LinkedIn’s social logon service, Amazon’s service, and MYDIGIPASS.com’s service. Check out the demonstration video below. Continue reading “SpoofedMe Attack Steals Accounts by Exploiting Social Login Mechanisms”

Hacking PayPal Accounts With CSRF

The computer security industry has made many positive changes since the early days of computing. One thing that seems to be catching on with bigger tech companies is bug bounty programs. PayPal offers such a program and [Yasser] decided to throw his hat in the ring and see if he could find any juicy vulnerabilities. His curiosity paid off big time.

Paypal is a huge player in the payment processing world, but that doesn’t mean they aren’t without their flaws. Sometimes the bigger the target, the more difficult it is to find problems. [Yasser] wanted to experiment with a cross-site request forgery attack. This type of attack typically requires the attacker to trick the victim into clicking a malicious link. The link would then impersonate the victim and make requests on the victim’s behalf. This is only made possible if the victim is logged into the target website.

PayPal has protection mechanisms in place to prevent this kind of thing, but [Yasser] found a loophole. When a user logs in to make a request, PayPal gives them an authentication token. This token is supposed to be valid for one user and one request only. Through experimentation, [Yasser] discovered a way to obtain a sort of “skeleton key” auth token. The attacker can attempt to initiate a payment transfer without first logging in to any PayPal account. Once the transfer is attempted, PayPal will request the user to authenticate. This process produces an auth token that apparently works for multiple requests from any user. It renders the authentication token almost entirely ineffective.

Once the attacker has a “universal auth token”, he can trick the victim into visiting a malicious web page. If the user is logged into their PayPal account at the time, the attacker’s webpage can use the universal auth token to trick the victim’s computer into making many different PayPal requests. Examples include adding email addresses to the account, changing the answers to security questions, and more. All of this can be done simply by tricking the user into clicking on a single link. Pretty scary.

[Yasser] was responsible with his disclosure, of course. He reported the bug to PayPal and reports that it was fixed promptly. It’s always great to see big companies like PayPal promoting responsible disclosure and rewarding it rather than calling the lawyers. Be sure to catch a video demonstration of the hack below. Continue reading “Hacking PayPal Accounts With CSRF”

Hiding Executable Javascript in Images That Pass Validation

Here’s an interesting proof-of-concept that could be useful or hazardous depending on the situation in which you encounter it. [jklmnn] drew inspiration from the work of [Ange Albertini] who has documented a way to hide Javascript within the header of a .gif file. Not only does it carry the complete code but both image and the Javascript are seen as valid.

With just a little bit of work [jklmnn] boiled down the concept to the most basic parts so that it is easy to understand. Next, a quick program was written to automate the embedding of the Javascript. Grab the source code if you want to give it a try yourself.

Let’s get back to how this might be useful rather than harmful. What if you are working on a computer that doesn’t allow the browser to load Javascript. You may be able to embed something useful, kind of like the hack that allowed movies to be played by abusing Microsoft Excel.

Echo, the First Useful Home Computer Intelligence?

We’re familiar with features like Siri or Microsoft’s Cortana which grope at a familiar concept from science fiction, yet leave us doing silly things like standing in public yowling at our phones. Amazon took a new approach to the idea of an artificial steward by cutting the AI free from our peripherals and making it an independent unit that acts in the household like any other appliance. Instead of steering your starship however, it can integrate with your devices via bluetooth to aide in tasks like writing shopping lists, or simply help you remember how many quarts are in a liter. Whatever you ask for, Echo will oblige.

Screen Shot 2014-11-06 at 2.57.14 PMThe device is little more than the internet and a speaker stuffed into a minimal black cylinder the size of a vase, oh- and six far-field microphones aimed in each direction which listen to every word you say… always. As you’d expect, Echo only processes what you say after you call it to attention by speaking its given name. If you happen to be too far away for the directional microphones to hear, you can alternatively seek assistance from the Echo app on another device. Not bad for the freakishly low price Amazons asking, which is $100 for Prime subscribers. Even if you’re salivating over the idea of this chatting obelisk, or intrigued enough to buy one just to check it out (and pop its little seams), they’re only available to purchase through invite at the moment… the likes of which are said to go out in a few weeks.

The notion of the internet at large acting as an invisible ever-present swiss-army-knife of knowledge for the home is admittedly pretty sweet. It pulls on our wishful heartstrings for futuristic technology. The success of Echo as a first of its kind however relies on how seamlessly (and quickly) the artificial intelligence within it performs. If it can hold up, or prove to hold up in further iterations, it’s exciting to think what larger systems the technology could be integrated with in the near future… We might have our command center consciousness sooner than we thought.

With that said, inviting a little WiFi probe into your intimate living space to listen in on everything you do will take some getting over… your thoughts?

Continue reading “Echo, the First Useful Home Computer Intelligence?”

Content Centric Networking and a tour of (Xerox) PARC

You may be used to seeing rack mounted equipment with wires going everywhere. But there’s nothing ordinary about what’s going on here. [Elecia White] and [Dick Sillman] are posing with the backbone servers they’ve been designing to take networking into the era that surpasses IPv6. That’s right, this is the stuff of the future, a concept called Content Centric Networking.

Join me after the break for more about CCN, and also a recap of my tour of PARC. This is the legendary Palo Alto Research Company campus where a multitude of inventions (like the computer mouse, Ethernet, you know… small stuff) sprang into being.

Continue reading “Content Centric Networking and a tour of (Xerox) PARC”