You probably have heard about AVIF already, but if not; it is a new image format which is based on the AV1 video format and generally has superior compression than the better-known WebP, JPEG, PNG and GIF formats. Avif is currently supported by Chrome & Opera and can be enabled by setting the image.avif.enabled flag in Firefox.
So there you have it, AVIF is now available in WordPress!
So AVIF is a new(ish) image format that promises even better optimization then WebP and is supported in desktop Chrome & behind a preference in Firefox; go to about:config and set image.avif.enabled to true.
If you are using Autoptimize to optimize your images and you want to test AVIF images, you can use below code snippet to do so;
With Autoptimize 2.7.7 released on August the 23rd and having been pushed to all sites that were still on 2.7.0-2.7.6 by the WordPress plugins team on Aug. 30th and 31th, resulting in just under one million downloads in 8 days time, it is now the moment for a small debrief of the security issues that were fixed in this version.
2.7.7 fixed two vulnerabilities, one authenticated cross-site scripting and one arbitrary file upload.
Risk: This could be abused by one administrator to execute JS against another administrator.
Problem: the code that processes Critical CSS settings imports did insufficient checks to ensure no malicious files were uploaded as it lacked a user capability check, did not check file extension of to uploaded file to be zip and did not check the contents of the zip-file. It did however check for a correct nonce for that specific action.
Risk: this could lead to authenticated attackers uploading PHP-files that could be executed, but that risk was very much limited by the nonce-check (which all exploits I have seen happily ignore).
Solution: the code has been updated to do a capability check, to make sure the file uploaded is a zip-file and most importantly to delete any unknown file found immediately after unzipping (based on an list of known-good files).
A big thank you to the two security researchers (Erin Germ for the XSS and an anonymous whitehatter for the file upload problem) who reported these vulnerabilities in a responsible manner and to the WordPress plugin team for their invaluable help in keeping our users safe.
Autoptimize 2.7.7, which was release earlier today, has misc. improvements, but more importantly comes with 2 security fixes (one XSS, one malicious file upload, both for authenticated users), so please upgrade sooner rather then later.