The IETF (Internet Engineering Task Force), which is responsible for the development of internet protocols and architecture, has published RFC 8996, officially classifying the TLS 1.0 and 1.1 protocols as obsolete technologies.
The TLS 1.0 specification was published in January 1999. Seven years later, TLS 1.1 was released with security improvements related to initialization vector generation and padding. According to the Pulse service, SSL as of January 16, 95.2% of websites allowing secure connections support TLS 1.2, while TLS 1.3 is supported by 14.2%. Connections using TLS 1.1 are permitted by 77.4% of HTTPS sites, and TLS 1.0 by 68%. Approximately 21% of the top 100,000 sites listed in the Alexa ranking still do not use HTTPS.
The main issues with TLS 1.0/1.1 are the lack of support for modern ciphers (such as ECDHE and AEAD) and the specification's requirement to support older ciphers, whose reliability has been questioned given the current advancements in computing (for instance, support for TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA is required, and MD5 and SHA-1 are used for integrity and authentication checks). Support for these outdated algorithms has already led to the emergence of attacks such as ROBOT, DROWN, BEAST, Logjam, and FREAK. However, these issues were not direct vulnerabilities of the protocol and were addressed at the implementation level. The TLS 1.0/1.1 protocols themselves do not contain critical vulnerabilities that could be exploited for practical attacks.
Source: opennet.ru
