What is Site Isolation in Web Brower's? How it Works.

  

What is Site Isolation in Web Brower's?

Site Isolation is a security feature that offers additional protection against some types of security bugs.  It makes it harder for untrustworthy websites to access or steal information from your accounts on other websites.

 

Websites typically cannot access each other's data inside the browser, thanks to code that enforces the Same Origin Policy.  Occasionally, security bugs are found in this code and malicious websites may try to bypass these rules to attack other websites. 

 

Site Isolation offers a second line of defence to make such attacks less likely to succeed.  It ensures that pages from different websites are always put into different processes, each running in a sandbox that limits what the process is allowed to do.  It also makes it possible to block the process from receiving certain types of sensitive data from other sites.  As a result, a malicious website will find it much more difficult to steal data from other sites, even if it can break some of the rules in its own process.

 

How Site Isolation works

The new Site Isolation security architecture acts as an additional security boundary between sites, and it works by completely separating users' web content, loading all sites in separate processes.

Thus, it prevents malicious websites from accessing private data (including passwords, credit card numbers, or other sensitive info) loaded from other sites.

For instance, with this new feature enabled, Browser's can protect users from attackers exploiting Meltdown and Spectre vulnerabilities that allow them to harvest sensitive data by reading memory content anywhere within a process's address space.

"Isolating each site into a separate operating system process makes it even harder for malicious sites to read another site’s secret or private data."

Besides obvious security advantages, Site Isolation also comes with performance Benefits:

• By placing more pages into separate processes, we can ensure that doing heavy computation or garbage collection on one page will not degrade the responsiveness of pages in other processes.
• Using more processes to load websites allows us to spread work across many CPU cores and use the underlying hardware more efficiently.
• Due to the finer-grained separation of sites, a subframe or a tab crashing will not affect websites loaded in different processes, resulting in improved application stability and better user experience.