January 14, 2016

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The Death of SSL 3.0 and TLSv1: Two Alternative Approaches to Data Encryption in the Aftermath of POODLE

Alternatives to TLS and SSL Blog Image

On October 14th, 2014, Google’s security team identified a serious vulnerability in the Security Sockets Layer (SSL) encryption protocol, POODLE. The Padding Oracle On Downgraded Legacy Encryption bug is a vulnerability that could allow a hacker to intercept data sent between a browser and a web server to extract sensitive information.

It has been discovered that SSL 3.0 contains a design flaw that in some cases can make it easily hackable. The green lock in your browser telling you that your information is safe wasn’t really accurate. While the full explanation of the vulnerability is enormously complex, and not that easy to pull off, the short explanation is that an issue with the integrity of the padding on SSL 3.0 block ciphers allows a hacker to conduct a man-in-the-middle attack. This essentially means that if the attacker places themselves within the communication channel of a user’s web browser and a web server, they can exploit the security vulnerability inherent to SSL 3.0 and eavesdrop on the data exchange or manipulate the data.

Well, at least, TLS, the more modern successor to SSL is safe, right?

A few months later, a similar vulnerability was identified within Transport Layer Security version 1.0 (TLSv1.0). If left improperly configured on the server, a hacker could force a downgrade from the TLS protocol to the older SSLv3.0 protocol and exploit the POODLE vulnerability. The only way to prevent this automatic downgrade is to disable SSL completely.

This means that neither SSLv3.0 nor TLSv1.0 are completely secure protocols with which to encrypt sensitive data. Many websites have still yet to adopt more secure encryption protocols such as TLSv1.1 or v1.2.

If your website deals with payment processing, healthcare information, or other sensitive data, it is imperative that you implement proper data encryption measures.

Luckily, there are a few practical steps you can take to bolster the security of your data encryption protocols – even if your server is using an older operating system.

Alternatives to SSLv3 and TLSv1.0

If you are running more modern operating system such as Windows 2008 R2 or Redhat/CentOS/Ubuntu, the fix can be fairly easy.

  • For Windows operating system, download a free copy of IISCrypo, click the PCI button and reboot.
  • For Linux, you would disable older versions of SSL within Apache (assuming that all other SSL-based services are not accessible outside your firewall)

What do you do if running on an older OS like Windows 2008 non R2? There are two practical ways to avoid exposure to the vulnerabilities inherent to SSLv3.0 and TLSv1.0:

  • Upgrade to a newer operating system that uses TLSv1.1 or 1.2
  • Implement a load balancer in front of your server and ensure it is also using TLSv1.1 or 1.2. The load balancer becomes the secure proxy for all of your traffic.

The first approach is a server level fix ensuring your operating system uses the latest data encryption protocol to protect sensitive data.

Windows 2008 R2 as well as Redhat/CentOS 5 and above, all implement TLSv1.1, which is the latest encryption protocols necessary to avoid the POODLE vulnerability. However, keep in mind, the upgrade is not enough. Since POODLE is a design flaw in SSL versions and the default installation does not disable it, you must completely disable TLS 1.0 and SSL 3.0 to ensure an attacker can’t implement a forced downgrade to earlier encryption protocols.

The second approach is applicable in cases where an OS upgrade is not feasible due to technical or financial constraints. It involves placing a load balancer in front of your server that listens on the port where external clients connect to access services. When the client initiates the connection, the load balancer (which uses TLSv1.1 or 1.2) handles the communication and becomes responsible for decrypting the SSL traffic before passing the request on to your server via a private communication channel creating a secure connection between the client and the load balancer.

The approach you decide to go with depends on your overarching security objectives, and the feasibility of upgrading to a newer operating system. Consulting with a managed hosting provider, like Edge Hosting, which specializes in security can often help you hone in on the ideal approach given your current web assets and data encryption needs.

Implementing secure data encryption protocols is a major concern for organizations that manage sensitive financial, health, or personal data.

The security vulnerabilities inherent to SSLv3.0 and TLSv1.0 are especially pertinent if your server uses an older OS or if you have not properly disabled vulnerable data encryption protocols that exist even on newer server operating systems.

If you aren’t sure if your site is affected, you can use the following online test from Qualys – https://www.ssllabs.com/ssltest/

Data encryption is only one aspect of an overall web-security plan. Protecting sensitive data take more than just ensuring the right encryption protocols are enabled. It takes a good security plan, the right technology, and a 24/7 operations team.

Here at Edge, we specialize in a holistic approach to data security that not only considers how to protect sensitive data now but how to proactively tackle security concerns in the future through a 5-tier security plan and 24/7/365 monitoring. A proactive approach to security will ensure that your data is both using advanced encryption techniques and that you are not leaving any other holes in your cyber security plan that could potentially expose sensitive client information.

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