Hacker News Reader

Comment by dexen | Hacker News Reader

(Hopefully) the OS enforces memory protection between the adblock process and any HTTP client process, thus limiting attacks to only the data that resides in, or flows through, the adblock process.

With a bit more advanced setup, you could also completely cut off the adblock process from accessing any files or any other resources related to the browser, further nailing down security.

Sure, it is possible to have similar (or equivalent) setup for browser plugins, but it requires some special engineering done in the browser - and in that scenario no other apps benefit from the protection. Let's not forget there's many more crucial HTTP user agents than just the web browser.

View on HN

>(Hopefully) the OS enforces memory protection between the adblock process and any HTTP client process, thus lowering the direct attack surface to only the data that resides in, or flows through, the adblock process.

>With a bit more advanced setup, you could even completely cut off the adblock process from accessing any files or any other resources related to the browser, further nailing down security.

How would that even work? The adblocking process has full access to whatever's being passed through it, and therefore it can eavesdrop or tamper (eg. inject malicious js) with the contents.

>Sure, it is possible to have similar (or equivalent) setup for browser plugins, but it requires some special engineering done in the browser - and in that scenario no other apps benefit from the protection. Let's not forget there's much more crucial HTTP user agents than just the browser.

Sounds useful, but it's a lot like dns based adblockers or hosts file, only worse because it only works locally, and only for applications that support/respect the proxy settings.

>>With a bit more advanced setup, you could even completely cut off the adblock process from accessing any files or any other resources related to the browser, further nailing down security.

>How would that even work? The adblocking process has full access to whatever's being passed through it, and therefore it can eavesdrop or tamper (eg. inject malicious js) with the contents.

A web browser is so much more than just the network traffic. Consider the mouse & keyboard input, the browsing history, the cache, the security credential store, the connection to display, GPU, USB and Bluetooth devices, microphones & cameras... the list goes on. This includes ability to read and write local files, start new processes, compile and run code. And then there are other HTTP user agents, like automatic software update tools.

Most of this functionality shouldn't be needed by, nor accessible to, an ad blocker.

Lastly, you could put much stricter resource usage limits (CPU time, operating memory) on an adblocking process than on a web browser, thwarting whole classes of resource exhausting attacks.

>only worse because it only works locally

You can apply varying levels of restricting any net traffic not passing through the adblock, up to and including dropping any such traffic. Ability to ad-filter HTTP traffic of an email client, RSS reader (i know, 2020) and similar user agents would be good.

>A web browser is so much more than just the network traffic. Consider the mouse & keyboard input, the browsing history, the cache, the security credential store, the connection to display, GPU, USB and Bluetooth devices, microphones & cameras... the list goes on.

Access to those resources are either gated behind a permission (which adblockers shouldn't have access to), or can be accessed by any website, in which case a malicious ad blocker can exploit by injecting its malicious js into the http response.

>Lastly, you could put much stricter resource usage limits (CPU time, operating memory) on an adblocking process than on a web browser, thwarting whole classes of resource exhausting attacks.

Seems theoretical to me. If your adblocker is a cryptominer, you probably have bigger issues. If whatever site you're going to is mounting DoS attacks on your adblocker, you probably don't want to stay on the site anyways.

>You can apply varying levels of restricting any net traffic not passing through the adblock, up to and including dropping any such traffic. Ability to ad-filter HTTP traffic of an email client, RSS reader (i know, 2020) and similar user agents would be good.

I'm not doubting whether it works, it's just that it's worse (or marginally better) than dns/hosts adblockers.

Reply on news.ycombinator.com