$redirect modifier does not fake Response.prototype.url

[piquark6046]

AdGuard Extension version

4.1.53

Browser version

Mozilla Firefox Developer Edition 110.0b6; Brave 1.47.186

OS version

Ubuntu 22.10

What filters do you have enabled?

AdGuard Base filter, AdGuard German filter, AdGuard Tracking Protection filter, AdGuard URL Tracking filter, List-KR

What Stealth Mode options do you have enabled?

No response

Issue Details

Response.prototype.url returns (Browser Extension)://(UUID)/web-accessible-resources/redirects/googlesyndication-adsbygoogle.js?secret=... if ||pagead2.googlesyndication.com/pagead/js/adsbygoogle.js$redirect=googlesyndication-adsbygoogle rule is applied.

A website can profile a visitor with the browser extension's UUID.
uBlock Origin 1.46.0 is not affected by this issue.

Expected Behavior

Response.prototype.url returns https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js.

Screenshots

No response

Additional Information

• https://listauthorschat.slack.com/archives/C010PK19W78/p1674828913893099
• duden.de: detection uBlockOrigin/uAssets#16430 (comment)

async function detectAdblock() {
    try{
        var googlead = 'https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js';
        var response = await fetch(googlead);
        var result = await response.text();
        if (result.length < 1000) {
            console.log("Adblock detected! response length is " + result.length + " but it should be larger than 1.000" );
        }
        if (response.url != googlead) {
            console.log("Adblock detected! response URL is " + response.url + " but it should be " + googlead);
        }
    }catch(e){
        console.log("Adblock detected! The request got blocked");
    }finally{
        // Unbreak the site when the script got executed
    }
  }
detectAdblock();

The above test code is provided by @JobcenterTycoon.

[ameshkov]

Check out this demo page as well:
https://adblock-testing.glitch.me/

[JobcenterTycoon]

Fixed the footer now.

[maximtop]

We have tried to fix this issue using base64 URLs, but in cases where a website has strict CSP policies, errors occur, and the redirect is not applied at all. An example of such problems can be seen here: #2913.