TLS protocol version 1.0 is deprecated and is now considered insecure by security researchers and standards organizations alike. For example, the PCI (Payment Card Industry) Security Standards Council requires that TLS 1.0 is disabled starting from mid-2018.

This version has a design flaw in the way encryption Initialization Vectors (IVs) are handled, and security researchers devised an attack called BEAST that may allow an attacker to eavesdrop on connections using TLS 1.0. However, note that TLS 1.0 is not immediately insecure, especially because BEAST is primarily a client-side attack, so if browsers are up-to-date, the connections should be safe.

In any case, the attacker needs to be able to eavesdrop and intercept the connection before being able to deliver the attack. This may be fairly common considering the frequency that clients establish connections over open Wi-Fi.

If you’d like to know more about secure TLS deployments, we have written an extensive article about it here.

How to fix

• generic
• nginx
• apache

• To fix this issue, you need to disable TLS 1.0. We also recommend that higher TLS protocol versions are enabled, ideally version 1.2 and above.

  For most systems, enabling or disabling TLS versions requires a change on the web server configuration file. Therefore, refer to your web server documentation on how to do that.

  If you are using Nginx, you may use the following snippet as a guideline:

  server {
      listen 443 ssl;
      ...
      ssl_protocols TLSv1.2 TLSv1.3;
      ...
  }
  

  If using an Apache server, please refer to the following example:

  <VirtualHost *:443>
      ...
      SSLProtocol        -all +TLSv1.2 +TLSv1.3
      ...
  </VirtualHost>
  

  Note that we are enabling TLS 1.2 and above, reflecting our ideal scenario.

  If you need to cater to clients with very old TLS support, such as ancient mobile devices, and know what you are doing, you can keep TLS 1.0 enabled, despite the known weaknesses. These issues are not as serious as the SSL protocol weaknesses, but you should weigh the need to support older clients with the risk of exposing private data. Moreover, keep in mind that TLS 1.2 support is well over 95%.

• To fix this issue you need to disable TLS 1.0. We also recommend that higher TLS protocol versions are enabled, ideally version 1.2 and above.

  For most systems, enabling or disabling TLS versions requires a change on the web server configuration file. Therefore, refer to your web server documentation on how to do that.

  For Nginx, you may use the following snippet as a guideline:

  server {
      listen 443 ssl;
      ...
      ssl_protocols TLSv1.2 TLSv1.3;
      ...
  }
  

  Note that we are enabling TLS 1.2 and above, reflecting our ideal scenario.

  If you need to cater to clients with very old TLS support, such as ancient mobile devices, and know what you are doing, you can keep TLS 1.0 enabled, despite the known weaknesses. These issues are not as serious as the SSL protocol weaknesses, but you should weight the need to support older clients with the risk of exposing private data. Moreover, keep in mind that TLS 1.2 support is well over 95%.

• To fix this issue you need to disable TLS 1.0. We also recommend that higher TLS protocol versions are enabled, ideally version 1.2 and above.

  For most systems, enabling or disabling TLS versions requires a change on the web server configuration file. Therefore, refer to your web server documentation on how to do that.

  If using an Apache server, please refer to the following example:

  <VirtualHost *:443>
      ...
      SSLProtocol        -all +TLSv1.2 +TLSv1.3
      ...
  </VirtualHost>
  

  Note that we are enabling TLS 1.2 and TLS 1.3, reflecting our ideal scenario.

  If you need to cater to clients with very old TLS support, such as ancient mobile devices, and know what you are doing, you can keep TLS 1.0 enabled, despite the known weaknesses. These issues are not as serious as the SSL protocol weaknesses, but you should weight the need to support older clients with the risk of exposing private data. Moreover, keep in mind that TLS 1.2 support is well over 95%.