Deprecations and removals in Chrome 93

Chrome 93 beta was released on July 29, 2021 and is expected to become the stable version in late August, 2021.

Block ports 989 and 990

Connections to HTTP, HTTPS or FTP servers on ports 989 and 990 now fail. These ports are used by the FTPS protocol, which has never been implemented in Chrome. However, FTPS servers can be attacked in a cross-protocol attack by malicious web pages using carefully-crafted HTTPS requests. This is a mitigation for the ALPACA attack.

Remove 3DES in TLS

Chrome has now removed support for the TLS_RSA_WITH_3DES_EDE_CBC_SHA cipher suite. TLS_RSA_WITH_3DES_EDE_CBC_SHA is a remnant of the SSL 2.0 and SSL 3.0 era. 3DES in transport layer security (TLS) is vulnerable to the Sweet32 attack. Being a CBC cipher suite, it is also vulnerable to the Lucky Thirteen attack. The first replacement AES cipher suites were defined for TLS in RFC3268, published around 19 years ago, and there have been several iterations since.

WebAssembly cross-origin module sharing

WebAssembly module sharing between cross-origin but same-site environments will be deprecated to allow agent clusters to be scoped to origins long term. This follows a WebAssembly specification change, which has an impact on the platform as well.

Deprecation policy

To keep the platform healthy, we sometimes remove APIs from the Web Platform which have run their course. There can be many reasons why we would remove an API, such as:

  • They are superseded by newer APIs.
  • They are updated to reflect changes to specifications to bring alignment and consistency with other browsers.
  • They are early experiments that never came to fruition in other browsers and thus can increase the burden of support for web developers.

Some of these changes will have an effect on a very small number of sites. To mitigate issues ahead of time, we try to give developers advanced notice so they can make the required changes to keep their sites running.

Chrome currently has a process for deprecations and removals of API's, essentially:

  • Announce on the blink-dev mailing list.
  • Set warnings and give time scales in the Chrome DevTools Console when usage is detected on the page.
  • Wait, monitor, and then remove the feature as usage drops.

You can find a list of all deprecated features on using the deprecated filter and removed features by applying the removed filter. We will also try to summarize some of the changes, reasoning, and migration paths in these posts.