Crashtest Security Blog

The ongoing changes of browser support for TLS 1.0 & 1.1

Apr 22, 2020 9:45:00 AM / by Janosch Maier

TLS 1.0 and 1.1 have been around for quite some time. TLS 1.0 was released in 1999, TLS 1.1 in 2006. They both should not be used anymore!
There are well known attacks such as Padding Oracle Attacks or BEAST for those versions. That is why Crashtest Security shows TLS 1.0 & 1.1 as critical vulnerabilities.

This article shows general industry guidelines, the usage of the protocol versions, and how different browser vendors are handling the deprecation of TLS 1.0 and TLS 1.1. We also help you to remediate a website or application that still uses TLS 1.0 or 1.1.

TLS 1.0 & 1.1 General industry guidelines

The Payment Card Industry Data Security Standard (PCI DSS) prohibits the usage of TLS 1.0 since June 30th, 2018. And the German Federal Office for Information Security, BSI (Bundesamt für Sicherheit in der Informationstechnik), recommends to not use TLS 1.1 because of its usage of the SHA-1 hash function which is not guaranteed to be collision-free.

The successors are easily available. TLS 1.2 was introduced in 2008 and is widely adopted by now. TLS 1.3 from year 2018 is uprising and more and more TLS stacks, webservers and load balancers support its usage.
If this does not convince you to stop using the old versions, probably the following might: All major browsers announced to stop the support for TLS 1.0 and 1.1 in the first quarter of 2020.

TLS 1.0 & TLS 1.1 Usage

Currently, the estimates of used TLS 1.0 and 1.1 connections are between 0,5% and 1.11% of all connections. Chromium mentioned above 0,5% of pageloads use one of the protocols in October 2019. Firefox saw 1.11% of connections using TLS 1.0 for Firefox Beta 62 in September 2018. For the past month (March/April 2020) and the latest release (beta 75), Firefox still shows 0,43% of connections through TLS 1.0 and 0,2 % through TLS 1.1(Measurement Dashboard).

TLS 1.0 & 1.1 Support of main browsers
- and how it changed over time

Google Chrome (and the Chrome-family browsers) already shows a huge notification that your website is insecure if a TLS 1.0 or 1.1 handshake is agreed upon:
Browser Not Secure Warning in Google Chrome
All major browsers planned to completely drop their support for TLS versions 1.0 and 1.1. However, most providers re-enabled the protocols due to the Corona virus, citing "enabling access to sites sharing critical and important information during this time" (Mozilla).
Below is an overview of the announcements.

Browser TLS-related change history
Google Chrome

Google announced the future removal of TLS 1.0 and 1.1 in Chrome 72. The article states that the protocols are currently deprecated. 
A warning in the browser was implemented with Chrome 79, according to ChromeStatus.
It also announced the removal of the protocols in Chrome 81, but later added a note that they the removal will be delayed to Chrome version 84, which is planned to ship in July 2020.
View the Removal history on ChromeStatus
Check out the Google Security Blog article on Transport Security.

Mozilla Firefox

Mozilla announced on October 15th 2018 to remove TLS 1.0 and TLS 1.1 in March 2020.
On February 6th, they released an announcement on the specific warnings around the protocols.
On March 23rd, they added the note to re-enable the protocols.

Microsoft Edge and Internet Explorer 11

On October 15th 2018, Microsoft announced the removal of the old TLS connections in Edge and IE for the first half of 2020.

On March 31st 2020, they added the note to disable the protocols in July 2020 (for the Chromium-based Edge version 84) and September 8th 2020 (for IE 11 and Microsoft Edge Legacy), respectively.
Microsoft also released a short blog post for this announcement.


Webkit published a guest post from Apple's Secure Transports team on October 15th of 2018 to completely remove the support beginning March 2020. 

So far, Apple has not released a statement to keep the protocol enabled. The release notes for the latest Safari release 13.1 show an added new feature to add a "not secure" warning for sites using TLS 1.1. and 1.0.

Where does this leave the cybersecurity community?

This is a difficult trade-off for browser providers. It seems unsafe that all major browser suppliers deferred to shut down the support of the old protocols amid a time that sees increased cybercrime activity. From a security perspective, it would be preferable that essential pages that still use TLS 1.0 and 1.1 perform an upgrade to the newer protocol versions. To put things in perspective, these protocols have been around for more than 20 years. Allowing a few extra months of support with implemented warnings are a calculated risk and worth it for people at home in distress with possible life-threatening problems. 

Take remediation action now

So as a vendor of a website or web application, you should ensure that your visitors have a secure way to visit your page. To verify that you have disabled these old TLS versions, simply check the result of your Crashtest Security Scan. It shows you the following information if any of those is still enabled:


You do not yet use Crashtest Security?
Then register for our 30 days free trial and conduct a scan of your web application. The SSL/TLS test is included in the Quick Scan functionality. For more protection, run a full scan that also tests for vulnerabilities like SQL Injection, Cross-Site-Scripting (XSS) and more!

If you found that your website or web application still supports TLS 1.0 or 1.1, have a look at our wiki page for secure TLS configuration or configuring trusted certificates or the PCI Migration Guidelines for the next steps.

Topics: WebApplicationSecurity, SecurityManagement, VulnerabilityAssessment, Cybersecurity

Janosch Maier

Written by Janosch Maier

Co-Founder @ Crashtest Security. I write and give workshops regarding Web Security

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