BugTraq
Windows Mail Find People DLL side loading vulnerability Mar 08 2016 09:49PM
Securify B.V. (lists securify nl) (1 replies)
Re: Windows Mail Find People DLL side loading vulnerability Mar 09 2016 12:18PM
Stefan Kanthak (stefan kanthak nexgo de) (1 replies)
"Securify B.V." wrote:

> ------------------------------------------------------------------------

> Windows Mail Find People DLL side loading vulnerability
> ------------------------------------------------------------------------

> Yorick Koster, September 2015

[...]

> - CVE-2016-0100
> - MS16-025: Security Update for Windows Library Loading to Address
> Remote Code Execution (3140709)
>
> ------------------------------------------------------------------------

> Tested versions
> ------------------------------------------------------------------------

> This issue was successfully verified on Windows Vista + Office 2010
> 32-bit.

This vulnerability demonstrates Microsoft's terrible SLOPPY coding
horror^Wpractice: it needs two mistakes to create this kind of bug!

"%CommonProgramFiles%\System\wab32res.dll" is (as its name implies)
a resource DLL, which means that it contains no code, but only
(localized) resources, and SHOULD (better: MUST) be loaded via
LoadLibraryEx("%CommonProgramFiles%\System\wab32res.dll", NULL, LOAD_LIBRARY_AS_DATAFILE)
to avoid the call of its DllMain() startup code!
See <https://msdn.microsoft.com/en-us/library/ms684179.aspx>

JFTR: LOAD_LIBRARY_AS_DATAFILE was introduced in the last millennium!

Either
LoadLibrary("%CommonProgramFiles%\System\wab32res.dll")
or
LoadLibraryEx("wab32res.dll", NULL, LOAD_LIBRARY_AS_DATAFILE)
were sufficient to avoid this vulnerability.

> ------------------------------------------------------------------------

> Fix
> ------------------------------------------------------------------------

> Microsoft released MS16-025 that fixes this vulnerability.

Have you checked how Microsoft fixed it?
Did they exercise all due diligence now, practised defense in depth
and replaced the call to
LoadLibrary("wab32res.dll")
with a call to
LoadLibraryEx("%CommonProgramFiles%\System\wab32res.dll", NULL, LOAD_LIBRARY_AS_DATAFILE)?

> ------------------------------------------------------------------------

> Details
> ------------------------------------------------------------------------

> https://www.securify.nl/advisory/SFY20150904/windows_mail_find_people_dl
l_side_loading_vulnerability.html

stay tuned
Stefan

[ reply ]
Re: Windows Mail Find People DLL side loading vulnerability Mar 09 2016 05:30PM
Securify B.V. (lists securify nl)


 

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