Entries Tagged "man-in-the-middle attacks"

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A Man-in-the-Middle Attack against a Password Reset System

This is nice work: “The Password Reset MitM Attack,” by Nethanel Gelerntor, Senia Kalma, Bar Magnezi, and Hen Porcilan:

Abstract: We present the password reset MitM (PRMitM) attack and show how it can be used to take over user accounts. The PRMitM attack exploits the similarity of the registration and password reset processes to launch a man in the middle (MitM) attack at the application level. The attacker initiates a password reset process with a website and forwards every challenge to the victim who either wishes to register in the attacking site or to access a particular resource on it.

The attack has several variants, including exploitation of a password reset process that relies on the victim’s mobile phone, using either SMS or phone call. We evaluated the PRMitM attacks on Google and Facebook users in several experiments, and found that their password reset process is vulnerable to the PRMitM attack. Other websites and some popular mobile applications are vulnerable as well.

Although solutions seem trivial in some cases, our experiments show that the straightforward solutions are not as effective as expected. We designed and evaluated two secure password reset processes and evaluated them on users of Google and Facebook. Our results indicate a significant improvement in the security. Since millions of accounts are currently vulnerable to the PRMitM attack, we also present a list of recommendations for implementing and auditing the password reset process.

Password resets have long been a weak security link.

BoingBoing post.

EDITED TO ADD (7/13): A couple of related papers.

Posted on July 3, 2017 at 6:01 AMView Comments

Separating the Paranoid from the Hacked

Sad story of someone whose computer became owned by a griefer:

The trouble began last year when he noticed strange things happening: files went missing from his computer; his Facebook picture was changed; and texts from his daughter didn’t reach him or arrived changed.

“Nobody believed me,” says Gary. “My wife and my brother thought I had lost my mind. They scheduled an appointment with a psychiatrist for me.”

But he built up a body of evidence and called in a professional cybersecurity firm. It found that his email addresses had been compromised, his phone records hacked and altered, and an entire virtual internet interface created.

“All my communications were going through a man-in-the-middle unauthorised server,” he explains.

It’s the “psychiatrist” quote that got me. I regularly get e-mails from people explaining in graphic detail how their whole lives have been hacked. Most of them are just paranoid. But a few of them are probably legitimate. And I have no way of telling them apart.

This problem isn’t going away. As computers permeate even more aspects of our lives, it’s going to get even more debilitating. And we don’t have any way, other than hiring a “professional cybersecurity firm,” of telling the paranoids from the victims.

Posted on June 26, 2017 at 12:30 PMView Comments

Is WhatsApp Hacked?

Forbes is reporting that the Israeli cyberweapons arms manufacturer Wintego has a man-in-the-middle exploit against WhatsApp.

It’s a weird story. I’m not sure how they do it, but something doesn’t sound right.

Another possibility is that CatchApp is malware thrust onto a device over Wi-Fi that specifically targets WhatsApp. But it’s almost certain the product cannot crack the latest standard of WhatsApp cryptography, said Matthew Green, a cryptography expert and assistant professor at the Johns Hopkins Information Security Institute. Green, who has been impressed by the quality of the Signal code, added: “They would have to defeat both the encryption to and from the server and the end-to-end Signal encryption. That does not seem feasible at all, even with a Wi-Fi access point.

“I would bet mundanely the password stuff is just plain phishing. You go to some site, it asks for your Google account, you type it in without looking closely at the address bar.

“But the WhatsApp stuff manifestly should not be vulnerable like that. Interesting.”

Neither WhatsApp nor the crypto whizz behind Signal, Moxie Marlinspike, were happy to comment unless more specific details were revealed about the tool’s capability. Either Wintego is embellishing what its real capability is, or it has a set of exploits that the rest of the world doesn’t yet know about.

Posted on October 4, 2016 at 1:47 PMView Comments

Leaked Product Demo from RCS Labs

We have leak from yet another cyberweapons arms manufacturer: the Italian company RCS Labs. Vice Motherboard reports on a surveillance video demo:

The video shows an RCS Lab employee performing a live demo of the company’s spyware to an unidentified man, including a tutorial on how to use the spyware’s control software to perform a man-in-the-middle attack and infect a target computer who wanted to visit a specific website.

RCS Lab’s spyware, called Mito3, allows agents to easily set up these kind of attacks just by applying a rule in the software settings. An agent can choose whatever site he or she wants to use as a vector, click on a dropdown menu and select “inject HTML” to force the malicious popup to appear, according to the video.

Mito3 allows customers to listen in on the target, intercept voice calls, text messages, video calls, social media activities, and chats, apparently both on computer and mobile platforms. It also allows police to track the target and geo-locate it thanks to the GPS. It even offers automatic transcription of the recordings, according to a confidential brochure obtained by Motherboard.

Slashdot thread

Posted on September 9, 2016 at 2:18 PMView Comments

Credential Stealing as an Attack Vector

Traditional computer security concerns itself with vulnerabilities. We employ antivirus software to detect malware that exploits vulnerabilities. We have automatic patching systems to fix vulnerabilities. We debate whether the FBI should be permitted to introduce vulnerabilities in our software so it can get access to systems with a warrant. This is all important, but what’s missing is a recognition that software vulnerabilities aren’t the most common attack vector: credential stealing is.

The most common way hackers of all stripes, from criminals to hacktivists to foreign governments, break into networks is by stealing and using a valid credential. Basically, they steal passwords, set up man-in-the-middle attacks to piggy-back on legitimate logins, or engage in cleverer attacks to masquerade as authorized users. It’s a more effective avenue of attack in many ways: it doesn’t involve finding a zero-day or unpatched vulnerability, there’s less chance of discovery, and it gives the attacker more flexibility in technique.

Rob Joyce, the head of the NSA’s Tailored Access Operations (TAO) group — basically the country’s chief hacker — gave a rare public talk at a conference in January. In essence, he said that zero-day vulnerabilities are overrated, and credential stealing is how he gets into networks: “A lot of people think that nation states are running their operations on zero days, but it’s not that common. For big corporate networks, persistence and focus will get you in without a zero day; there are so many more vectors that are easier, less risky, and more productive.”

This is true for us, and it’s also true for those attacking us. It’s how the Chinese hackers breached the Office of Personnel Management in 2015. The 2014 criminal attack against Target Corporation started when hackers stole the login credentials of the company’s HVAC vendor. Iranian hackers stole US login credentials. And the hacktivist that broke into the cyber-arms manufacturer Hacking Team and published pretty much every proprietary document from that company used stolen credentials.

As Joyce said, stealing a valid credential and using it to access a network is easier, less risky, and ultimately more productive than using an existing vulnerability, even a zero-day.

Our notions of defense need to adapt to this change. First, organizations need to beef up their authentication systems. There are lots of tricks that help here: two-factor authentication, one-time passwords, physical tokens, smartphone-based authentication, and so on. None of these is foolproof, but they all make credential stealing harder.

Second, organizations need to invest in breach detection and — most importantly — incident response. Credential-stealing attacks tend to bypass traditional IT security software. But attacks are complex and multi-step. Being able to detect them in process, and to respond quickly and effectively enough to kick attackers out and restore security, is essential to resilient network security today.

Vulnerabilities are still critical. Fixing vulnerabilities is still vital for security, and introducing new vulnerabilities into existing systems is still a disaster. But strong authentication and robust incident response are also critical. And an organization that skimps on these will find itself unable to keep its networks secure.

This essay originally appeared on Xconomy.

EDITED TO ADD (5/23): Portuguese translation.

Posted on May 4, 2016 at 6:51 AMView Comments

Breaking Diffie-Hellman with Massive Precomputation (Again)

The Internet is abuzz with this blog post and paper, speculating that the NSA is breaking the Diffie-Hellman key-exchange protocol in the wild through massive precomputation.

I wrote about this at length in May when this paper was first made public. (The reason it’s news again is that the paper was just presented at the ACM Computer and Communications Security conference.)

What’s newly being talked about his how this works inside the NSA surveillance architecture. Nicholas Weaver explains:

To decrypt IPsec, a large number of wiretaps monitor for IKE (Internet Key Exchange) handshakes, the protocol that sets up a new IPsec encrypted connection. The handshakes are forwarded to a decryption oracle, a black box system that performs the magic. While this happens, the wiretaps also record all traffic in the associated IPsec connections.

After a period of time, this oracle either returns the private keys or says “i give up”. If the oracle provides the keys, the wiretap decrypts all the stored traffic and continues to decrypt the connection going forward.

[…]

This would also better match the security implications: just the fact that the NSA can decrypt a particular flow is a critical secret. Forwarding a small number of potentially-crackable flows to a central point better matches what is needed to maintain such secrecy.

Thus by performing the decryption in bulk at the wiretaps, complete with hardware acceleration to keep up with the number of encrypted streams, this architecture directly implies that the NSA can break a massive amount of IPsec traffic, a degree of success which implies a cryptanalysis breakthrough.

That last paragraph is Weaver explaining how this attack matches the NSA rhetoric about capabilities in some of their secret documents.

Now that this is out, I’m sure there are a lot of really upset people inside the NSA.

EDITED TO ADD (11/15): How to protect yourself.

Posted on October 16, 2015 at 6:19 AMView Comments

China's "Great Cannon"

Interesting research: “An Analysis of China’s ‘Great Cannon.’

Abstract: On March 16th, 2015, the Chinese censorship apparatus employed a new tool, the “Great Cannon”, to engineer a denial-of-service attack on GreatFire.org, an organization dedicated to resisting China’s censorship. We present a technical analysis of the attack and what it reveals about the Great Cannon’s working, underscoring that in essence it constitutes a selective nation-state Man-in-the-Middle attack tool. Although sharing some code similarities and network locations with the Great Firewall, the Great Cannon is a distinct tool, designed to compromise foreign visitors to Chinese sites. We identify the Great Cannon’s operational behavior, localize it in the network topology, verify its distinctive side-channel, and attribute the system as likely operated by the Chinese government. We also discuss the substantial policy implications raised by its use, including the potential imposition on any user whose browser might visit (even inadvertently) a Chinese web site.

Posted on September 4, 2015 at 8:16 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.