what you don't know can hurt you

Microsoft Internet Explorer 6 / 7 Use-After-Free

Microsoft Internet Explorer 6 / 7 Use-After-Free
Posted Jul 15, 2013
Authored by Yuhong Bao

This is a brief summary of how a security researcher discovered a use-after-free vulnerability in Microsoft Internet Explorer versions 6 and 7.

tags | advisory
advisories | CVE-2013-1310
MD5 | 9e203fe8068772588301b4507a4b0e3a

Microsoft Internet Explorer 6 / 7 Use-After-Free

Change Mirror Download
(this is the plain text version of http://yuhongbao.blogspot.ca/2013/07/how-i-found-cve-2013-1310.html)

>From http://www.satzansatz.de/cssd/pseudocss.html under "Application instability: another element adjacent to the pseudo-element":
"Now, when such a .ipsum construct gains "layout" by a subset of layout properties (position: absolute; / float: any value; / display: inline-block; / zoom: 1;), what will happen? Right. Some will have to cancel the frozen process, others will have to reboot, data gets lost. Don't do it. (No, I don't link to a testcase here. IE7b3 is still crashing after scrolling/resizing. Depending on the memory already burned, you might have difficulties to stop the process...)"

I created this test manually (save http://www.satzansatz.de/cssd/pseudocss/pseudocss_t004.html and add zoom: 1 to .ipsum) and not only this bug is still in final IE7, I also noticed that there is also a potentially exploitable crash bug by opening the about box after opening this page. When this happens, it crashes with EIP at an address like 0x790070.

After this, by adding onclick="window.showModalDialog('target.htm')" to <p class="ipsum">, creating the target.htm, then opening the page and clicking inside the box, I triggered various crashes including attempts at executing data (note that IE7 do not enable DEP by default) and heap termination on corruption.

I turned full pageheap on and after I did so it crashes reliably at:
(360.51c): Access violation - code c0000005 (first/second chance not available)
eax=00000004 ebx=08042e78 ecx=0000000a edx=065acfa0 esi=08042e78 edi=065289c0
eip=3ceff096 esp=04d04ba8 ebp=04d04bf8 iopl=0         nv up ei pl zr na pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000                  efl=00000246
mshtml!CLineCore::AssignLine+0x37:
3ceff096 f3a5 rep movs dword ptr es:[edi],dword ptr [esi]

MS fixed this bug in the May 2013 Cumulative Update for IE6 and IE7.

Here is http://www.satzansatz.de/cssd/pseudocss.html rendered in IE6 and IE7 before the patch:
http://imgur.com/qrcpNua

After the patch (notice it is the same rendering as IE8+ in IE7 compat mode):
http://imgur.com/BY6MTFc

Yuhong Bao

Comments

RSS Feed Subscribe to this comment feed

No comments yet, be the first!

Login or Register to post a comment

File Archive:

June 2019

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

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2019 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close