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MS15-001 Microsoft Windows NtApphelpCacheControl Improper Authorization Check

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MS15-001 Microsoft Windows NtApphelpCacheControl Improper Authorization Check

Disclosed
09/30/2014
Created
05/30/2018

Description

On Windows, the system call NtApphelpCacheControl (the code is actually in ahcache.sys) allows application compatibility data to be cached for quick reuse when new processes are created. A normal user can query the cache but cannot add new cached entries as the operation is restricted to administrators. This is checked in the function AhcVerifyAdminContext. This function has a vulnerability where it doesn't correctly check the impersonation token of the caller to determine if the user is an administrator. It reads the caller's impersonation token using PsReferenceImpersonationToken and then does a comparison between the user SID in the token to LocalSystem's SID. It doesn't check the impersonation level of the token so it's possible to get an identify token on your thread from a local system process and bypass this check. This module currently only affects Windows 8 and Windows 8.1, and requires access to C:\Windows\System\ComputerDefaults.exe (although this can be improved).

Author(s)

  • James Forshaw
  • sinn3r <sinn3r@metasploit.com>

Platform

Windows

Architectures

x86, x64

Development

References

Module Options

To display the available options, load the module within the Metasploit console and run the commands 'show options' or 'show advanced':

msf > use exploit/windows/local/ntapphelpcachecontrol
msf exploit(ntapphelpcachecontrol) > show targets
    ...targets...
msf exploit(ntapphelpcachecontrol) > set TARGET < target-id >
msf exploit(ntapphelpcachecontrol) > show options
    ...show and set options...
msf exploit(ntapphelpcachecontrol) > exploit

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