Entries Tagged "certificates"

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Security Vulnerabilities in Certificate Pinning

New research found that many banks offer certificate pinning as a security feature, but fail to authenticate the hostname. This leaves the systems open to man-in-the-middle attacks.

From the paper:

Abstract: Certificate verification is a crucial stage in the establishment of a TLS connection. A common security flaw in TLS implementations is the lack of certificate hostname verification but, in general, this is easy to detect. In security-sensitive applications, the usage of certificate pinning is on the rise. This paper shows that certificate pinning can (and often does) hide the lack of proper hostname verification, enabling MITM attacks. Dynamic (black-box) detection of this vulnerability would typically require the tester to own a high security certificate from the same issuer (and often same intermediate CA) as the one used by the app. We present Spinner, a new tool for black-box testing for this vulnerability at scale that does not require purchasing any certificates. By redirecting traffic to websites which use the relevant certificates and then analysing the (encrypted) network traffic we are able to determine whether the hostname check is correctly done, even in the presence of certificate pinning. We use Spinner to analyse 400 security-sensitive Android and iPhone apps. We found that 9 apps had this flaw, including two of the largest banks in the world: Bank of America and HSBC. We also found that TunnelBear, one of the most popular VPN apps was also vulnerable. These apps have a joint user base of tens of millions of users.

News article.

Posted on December 8, 2017 at 6:15 AMView Comments

Let's Encrypt Is Making Web Encryption Easier

That’s the conclusion of a research paper:

Once [costs and complexity] are eliminated, it enables big hosting providers to issue and deploy certificates for their customers in bulk, thus quickly and automatically enable encryption across a large number of domains. For example, we have shown that currently, 47% of LE certified domains are hosted at three large hosting companies (Automattic/wordpress.com, Shopify, and OVH).

Paper: “No domain left behind: is Let’s Encrypt democratizing encryption?

Abstract: The 2013 National Security Agency revelations of pervasive monitoring have lead to an “encryption rush” across the computer and Internet industry. To push back against massive surveillance and protect users privacy, vendors, hosting and cloud providers have widely deployed encryption on their hardware, communication links, and applications. As a consequence, the most of web traffic nowadays is encrypted. However, there is still a significant part of Internet traffic that is not encrypted. It has been argued that both costs and complexity associated with obtaining and deploying X.509 certificates are major barriers for widespread encryption, since these certificates are required to established encrypted connections. To address these issues, the Electronic Frontier Foundation, Mozilla Foundation, and the University of Michigan have set up Let’s Encrypt (LE), a certificate authority that provides both free X.509 certificates and software that automates the deployment of these certificates. In this paper, we investigate if LE has been successful in democratizing encryption: we analyze certificate issuance in the first year of LE and show from various perspectives that LE adoption has an upward trend and it is in fact being successful in covering the lower-cost end of the hosting market.

Reddit thread.

Posted on December 14, 2016 at 6:46 AMView Comments

Suckfly

Suckfly seems to be another Chinese nation-state espionage tool, first stealing South Korean certificates and now attacking Indian networks.

Symantec has done a good job of explaining how Suckfly works, and there’s a lot of good detail in the blog posts. My only complaint is its reluctance to disclose who the targets are. It doesn’t name the South Korean companies whose certificates were stolen, and it doesn’t name the Indian companies that were hacked:

Many of the targets we identified were well known commercial organizations located in India. These organizations included:

  • One of India’s largest financial organizations
  • A large e-commerce company
  • The e-commerce company’s primary shipping vendor
  • One of India’s top five IT firms
  • A United States healthcare provider’s Indian business unit
  • Two government organizations

Suckfly spent more time attacking the government networks compared to all but one of the commercial targets. Additionally, one of the two government organizations had the highest infection rate of the Indian targets.

My guess is that Symantec can’t disclose those names, because those are all customers and Symantec has confidentiality obligations towards them. But by leaving this information out, Symantec is harming us all. We have to make decisions on the Internet all the time about who to trust and who to rely on. The more information we have, the better we can make those decisions. And the more companies are publicly called out when their security fails, the more they will try to make security better.

Symantec’s motivation in releasing information about Suckfly is marketing, and that’s fine. There, its interests and the interests of the research community are aligned. But here, the interests diverge, and this is the value of mandatory disclosure laws.

Posted on May 26, 2016 at 6:31 AMView Comments

Economic Failures of HTTPS Encryption

Interesting paper: “Security Collapse of the HTTPS Market.” From the conclusion:

Recent breaches at CAs have exposed several systemic vulnerabilities and market failures inherent in the current HTTPS authentication model: the security of the entire ecosystem suffers if any of the hundreds of CAs is compromised (weakest link); browsers are unable to revoke trust in major CAs (“too big to fail”); CAs manage to conceal security incidents (information asymmetry); and ultimately customers and end users bear the liability and damages of security incidents (negative externalities).

Understanding the market and value chain for HTTPS is essential to address these systemic vulnerabilities. The market is highly concentrated, with very large price differences among suppliers and limited price competition. Paradoxically, the current vulnerabilities benefit rather than hurt the dominant CAs, because among others, they are too big to fail.

Posted on November 28, 2014 at 6:26 AMView Comments

A New Free CA

Announcing Let’s Encrypt, a new free certificate authority. This is a joint project of EFF, Mozilla, Cisco, Akamai, and the University of Michigan.

This is an absolutely fantastic idea.

The anchor for any TLS-protected communication is a public-key certificate which demonstrates that the server you’re actually talking to is the server you intended to talk to. For many server operators, getting even a basic server certificate is just too much of a hassle. The application process can be confusing. It usually costs money. It’s tricky to install correctly. It’s a pain to update.

Let’s Encrypt is a new free certificate authority, built on a foundation of cooperation and openness, that lets everyone be up and running with basic server certificates for their domains through a simple one-click process.

[…]

The key principles behind Let’s Encrypt are:

  • Free: Anyone who owns a domain can get a certificate validated for that domain at zero cost.
  • Automatic: The entire enrollment process for certificates occurs painlessly during the server’s native installation or configuration process, while renewal occurs automatically in the background.
  • Secure: Let’s Encrypt will serve as a platform for implementing modern security techniques and best practices.
  • Transparent: All records of certificate issuance and revocation will be available to anyone who wishes to inspect them.
  • Open: The automated issuance and renewal protocol will be an open standard and as much of the software as possible will be open source.
  • Cooperative: Much like the underlying Internet protocols themselves, Let’s Encrypt is a joint effort to benefit the entire community, beyond the control of any one organization.

Slashdot thread. Hacker News thread.

EDITED TO ADD (11/19): Good post. And EFF’s blog post.

Posted on November 18, 2014 at 12:38 PMView Comments

Forged SSL Certificates Pervasive on the Internet

About 0.2% of all SSL certificates are forged. This is the first time I’ve ever seen a number based on real data. News article:

Of 3.45 million real-world connections made to Facebook servers using the transport layer security (TLS) or secure sockets layer protocols, 6,845, or about 0.2 percent of them, were established using forged certificates.

Actual paper.

EDITED TO ADD (6/13): I’m mis-characterizing the study. The study really says that 0.2% of HTTPS traffic to Facebook is intercepted and re-signed, and the vast majority of that interception and resigning happens either on the user’s local computer (by way of trusted security software which is acting scanning proxy) or locally on a private network behind a corporation’s intercepting proxy/firewall. Only a small percentage of intercepted traffic is a result of malware or other nefarious activity.

Posted on May 16, 2014 at 6:43 AMView Comments

Microsoft Retiring SHA-1 in 2016

I think this is a good move on Microsoft’s part:

Microsoft is recommending that customers and CA’s stop using SHA-1 for cryptographic applications, including use in SSL/TLS and code signing. Microsoft Security Advisory 2880823 has been released along with the policy announcement that Microsoft will stop recognizing the validity of SHA-1 based certificates after 2016.

More news.

SHA-1 isn’t broken yet in a practical sense, but the algorithm is barely hanging on and attacks will only get worse. Migrating away from SHA-1 is the smart thing to do.

Posted on November 13, 2013 at 2:17 PMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.