eEye Advisories
16/11/06, 02:41
eEye Research - http://research.eeye.com
Workstation Service NetpManageIPCConnect Buffer Overflow
Release Date:
November 14, 2006
Date Reported:
July 25, 2006
Severity:
High (Remote Code Execution)
Vendor:
Microsoft
Systems Affected:
Windows 2000 (Remote Code Execution)
Windows XP SP1 (Local Privilege Escalation)
Overview:
A flaw exists in a default Windows component called the "Workstation
Service" that when exploited allows for remote code execution in SYSTEM
context, allowing an attacker to take complete control of affected
systems.
Technical Details:
In the Workstation Service module called wkssvc.dll, the
NetpManageIPCConnect function has a call to "swprintf" with an unchecked
buffer. The input buffer is controllable by the remote attacker.
.text:76781D67 mov edi, [ebp+arg_0]
...
.text:76781D90 lea eax, [ebp+var_2CC]
...
.text:76781DA0 push edi
.text:76781DA1 push offset "%ws\\IPC$"
.text:76781DA6 push eax
.text:76781DA7 call ds:swprintf
This function is called by NetpJoinDomain, which is eventually called by
the NetrJoinDomain2 function, which is exposed through RPC.
The IDL for NetrJoinDomain2 looks like this:
long _NetrJoinDomain2@28 (
[in][unique][string] wchar_t * arg_1,
[in][string] wchar_t * arg_2,=20
[in][unique][string] wchar_t * arg_3,
[in][unique][string] wchar_t * arg_4,
[in][unique] struct_C * arg_5,
[in] long arg_6
);
arg_2 will contain string with format like <Domain name>+"\"+<Hostname>.
<Hostname> will be passed as NetpManageIPCConnect's first argument. The
variable is under the attacker's control and is passed to swprintf,
which causes a stack-based buffer overflow.
For this vulnerable code to be reached, we must provide a valid and live
<Domain name> as a part of the string. We can set up a fake domain
server anywhere reachable from the vulnerable machine on the Internet.
P.S. If you despise Birkenstocks, are not afraid of your Tequila, and
are well versed in reverse engineering, bug finding, or are looking to
learn, we are hiring both junior and senior security researchers. Send
your resume (blathering of college course work, degrees, and past
experience we don't care about) or more importantly a description of why
you would be a good researcher to skunkworks@eeye.com.
Credit:
Discovery: JeongWook Matt Oh
Additional Research: Derek Soeder
Related Links:
Retina Network Security Scanner - Free Trial
Blink Endpoint Vulnerability Prevention - Free Trial
Greetings:
Dugsong, Ohhara, Ryan Lee, Pilot, Sakai, Gonan and all the Korean
Bugtruck Mailing List Subscribers
Copyright (c) 1998-2006 eEye Digital Security
Permission is hereby granted for the redistribution of this alert
electronically. It is not to be edited in any way without express
consent of eEye. If you wish to reprint the whole or any part of this
alert in any other medium excluding electronic medium, please email
alert@eEye.com for permission.
Disclaimer
The information within this paper may change without notice. Use of
this information constitutes acceptance for use in an AS IS condition.
There are no warranties, implied or express, with regard to this
information. In no event shall the author be liable for any direct or
indirect damages whatsoever arising out of or in connection with the use
or spread of this information. Any use of this information is at the
user's own risk.
Workstation Service NetpManageIPCConnect Buffer Overflow
Release Date:
November 14, 2006
Date Reported:
July 25, 2006
Severity:
High (Remote Code Execution)
Vendor:
Microsoft
Systems Affected:
Windows 2000 (Remote Code Execution)
Windows XP SP1 (Local Privilege Escalation)
Overview:
A flaw exists in a default Windows component called the "Workstation
Service" that when exploited allows for remote code execution in SYSTEM
context, allowing an attacker to take complete control of affected
systems.
Technical Details:
In the Workstation Service module called wkssvc.dll, the
NetpManageIPCConnect function has a call to "swprintf" with an unchecked
buffer. The input buffer is controllable by the remote attacker.
.text:76781D67 mov edi, [ebp+arg_0]
...
.text:76781D90 lea eax, [ebp+var_2CC]
...
.text:76781DA0 push edi
.text:76781DA1 push offset "%ws\\IPC$"
.text:76781DA6 push eax
.text:76781DA7 call ds:swprintf
This function is called by NetpJoinDomain, which is eventually called by
the NetrJoinDomain2 function, which is exposed through RPC.
The IDL for NetrJoinDomain2 looks like this:
long _NetrJoinDomain2@28 (
[in][unique][string] wchar_t * arg_1,
[in][string] wchar_t * arg_2,=20
[in][unique][string] wchar_t * arg_3,
[in][unique][string] wchar_t * arg_4,
[in][unique] struct_C * arg_5,
[in] long arg_6
);
arg_2 will contain string with format like <Domain name>+"\"+<Hostname>.
<Hostname> will be passed as NetpManageIPCConnect's first argument. The
variable is under the attacker's control and is passed to swprintf,
which causes a stack-based buffer overflow.
For this vulnerable code to be reached, we must provide a valid and live
<Domain name> as a part of the string. We can set up a fake domain
server anywhere reachable from the vulnerable machine on the Internet.
P.S. If you despise Birkenstocks, are not afraid of your Tequila, and
are well versed in reverse engineering, bug finding, or are looking to
learn, we are hiring both junior and senior security researchers. Send
your resume (blathering of college course work, degrees, and past
experience we don't care about) or more importantly a description of why
you would be a good researcher to skunkworks@eeye.com.
Credit:
Discovery: JeongWook Matt Oh
Additional Research: Derek Soeder
Related Links:
Retina Network Security Scanner - Free Trial
Blink Endpoint Vulnerability Prevention - Free Trial
Greetings:
Dugsong, Ohhara, Ryan Lee, Pilot, Sakai, Gonan and all the Korean
Bugtruck Mailing List Subscribers
Copyright (c) 1998-2006 eEye Digital Security
Permission is hereby granted for the redistribution of this alert
electronically. It is not to be edited in any way without express
consent of eEye. If you wish to reprint the whole or any part of this
alert in any other medium excluding electronic medium, please email
alert@eEye.com for permission.
Disclaimer
The information within this paper may change without notice. Use of
this information constitutes acceptance for use in an AS IS condition.
There are no warranties, implied or express, with regard to this
information. In no event shall the author be liable for any direct or
indirect damages whatsoever arising out of or in connection with the use
or spread of this information. Any use of this information is at the
user's own risk.