The release of uBlock Origin 1.2.5 is a fact and brings with it a new one feature preventing first-party tracking scripts, which use DNS CNAME, to load tracking scripts from a third domain to bypass filters.
A first-party tracking script is defined as the script that is loaded directly from a subdomain of the site Web that the script is loaded. For example, if “www.example.com” had uploaded a script from “tracking.example.com”, this is considered a first-party tracking script, as they share the same domain.
Since uBlock Origin could block tracking scripts originating from third-party domains or otherwise uploaded from another domain, tracking companies have discovered a new insidious method to use CNAME documents to load first-party tracking scripts.
For example, 'tracking.example.com' would use a CNAME document to load a script from 'www.badtracker.com'. Although the script is loaded from a remote site, uBlock Origin still views it as a first-party tracking script because the page's HTML loads it from the same domain as site.
The new uBlock will prevent such cases
On February 19, 2020, uBlock Origin 1.2.5 was released, which allows ad blockers to block these scripts, performing a DNS search before loading them.
If it is subdomains is CNAME on a third host, then uBlock Origin will prevent the script from loading.
When loaded, uBlock Origin will now display a new license entitled 'IP address access and information hosting'allowing uBlock to use the DNS API.
To download uBlock Origin visit him Mozilla Add-Ons site or if you already have it installed you can check for the new update by going to the Firefox Extensions page and clicking 'Check for Updates'.