------------------------------------------------------------------------ Shutdown UX DLL side loading vulnerability ------------------------------------------------------------------------ Yorick Koster, November 2015 ------------------------------------------------------------------------ Abstract ------------------------------------------------------------------------ A DLL side loading vulnerability was found in the Shutdown UX DLL. This issue can be exploited by loading the Authentication UI Shutdown Choices object as an embedded OLE object. When instantiating the object Windows will try to load the DLL wuaext.dll from the current working directory. If an attacker convinces the user to open a specially crafted (Office) document from a directory also containing the attacker's DLL file, it is possible to execute arbitrary code with the privileges of the target user. This can potentially result in the attacker taking complete control of the affected system. ------------------------------------------------------------------------ See also ------------------------------------------------------------------------ http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-6128 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-6132 https://technet.microsoft.com/library/security/MS15-132 https://securify.nl/blog/SFY20151201/there_s_a_party_in_ole__and_you_are_invited.html ------------------------------------------------------------------------ Tested versions ------------------------------------------------------------------------ This issue was successfully verified on Windows 10 + Office 2016 64-bit. ------------------------------------------------------------------------ Fix ------------------------------------------------------------------------ Microsoft released MS15-132 [4] that fixes this vulnerability. ------------------------------------------------------------------------ Details ------------------------------------------------------------------------ https://www.securify.nl/advisory/SFY20151102/shutdown_ux_dll_side_loading_vulnerability.html
