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.