As a security-conscious user, I’ve used NoScript since Firefox’s early days, but its restrictive nature has become frustrating. I’m often forced to go unprotected just to access websites with multiple scripts running on different domains, which defeats the purpose of using NoScript and balances security and usability that it once provided.
Is there a way to block browser JavaScript from executing commands that retrieve sensitive information from my local machine, while still allowing JavaScript that is only used for rendering web pages?
by sensitive information I’m referring to
- local machine time
- local machine ram
- local machine operating system + version
- local machine hardware
- Serial Number
- Hardware ID
- UUID
- Windows Device ID
- Windows Product ID
- …
greatly appreciate any insight
Some browsers have built in fingerprint resistance techniques you can enable:
https://support.mozilla.org/en-US/kb/resist-fingerprinting
I wouldn’t entirely trust it, but enabling this feature in strict mode would tick a few of your listed boxes.
Harsh question: Do you have a real need to prevent this data from being collected, or are you investigating just for
funsiesbest practice advice? There are a lot of posts like this where people overestimate the threat model they have and insist on needing to block things that are nearly impossible to, or at least have significant tradeoffs like you are dealing with now.Javascript is also not the only source that sites can use for these pieces of info from your machine. Local time in particular can be estimated by looking up the rough location of your IP address then matching to a time zone.
Anyway.
I would assume you could technically fork localCDN (replaces remote javascript libraries with local copies) and then manually edit the local javascript library copies to remove the calls you are concerned about.
There’s also options like uBlock Origin’s methods of only whitelisting specific scripts. Much more flexible than NoScript. You can block scripts that are third party and only allow site specific ones fairly easily, without digging deep into the settings.
Bear in mind that your specific combination of installed extensions can also be a unique identifier though.
This is the closest thing I have found
Depends what you mean by local information
Your best method:
Use a socksv5 proxy with your browser so it can’t connect to localhost
Use a incognito browser for the login session
Use a socksv5 proxy with your browser so it can’t connect to localhost
Website is able to get info of localhost?
Does this mean they are able to see what docker container I’m hosting?
many browsers allow connection to localhost ports, this is how discord opens discord links in the app and not the browser on people’s desktop computers.
I see, could you link to an article or video that explains more about how this is achieved? Is there a browser extension to disable a website from accessiing localhost connection?
socksv5 proxies, or you could dig into the settings and find a option to disable local connections (not sure where)
by sensitive information I’m referring to
- local machine time
- local machine ram
- local machine operating system + version
- local machine hardware
- Serial Number
- Hardware ID
- UUID
- Windows Device ID
- Windows Product ID
- …
Can I prevent javascript from running specific command that retrieve these information?
If any of that information is critical, you should not be running JavaScript. You should remote into a virtual machine and then browse from there.
Even the tor browser bundle gives away machine architecture
Personally I think a websites requires machine architecture is dubious and necessary, webpage should be functional without those info
your not wrong, but every browser exposes it via javascript. so if that is part of your threat model you can’t use a local browser.
maybe jshelter can help?
Javascript can’t generally access your local machine directly, but scoped local data like cookies are available. What in particular are you nervous about? You could run your browser in a virtual machine?
by sensitive information I’m referring to
- local machine time
- local machine ram
- local machine operating system + version
- local machine hardware
- Serial Number
- Hardware ID
- UUID
- Windows Device ID
- Windows Product ID
- …
Can I prevent javascript from running specific command that retrieve these information?
You could monkeypatch some javascript functions like the constructor Date types, but there will always be things not thought of that will leak date info. Hardware identifiers are quite difficult to get in javascript and several browsers already obfuscate that info.
Honestly if you’re very concerned, I really do think a virtual machine is your absolute safest approach, obviously the browsing experience is worse.
Check out amiunique.org to see what fingerprinting is generally available in your current browser
Have you looked into Pi-hole?
from my understanding it is a dns blocker, not sure how it is related though, could you elaborate?
