| VID |
26041 |
| Severity |
40 |
| Port |
139,445 |
| Protocol |
TCP |
| Class |
SMB |
| Detailed Description |
The hotfix (Q815021) for 'unchecked buffer in Windows component, ntdll.dll' is not applied. An overflow in a path conversion function occurs within NtDLL, which is called from a common API exported from the Kernel32 library.
However, the specific API in question is reachable through the WebDAV component of IIS 5.0. The API does not appear to be vulnerable on Windows XP or Windows Server 2003. IIS 4.0 does not have WebDAV enabled by default. WebDAV, defined in RFC 2518, is a set of extensions to the Hyper Text Transfer Protocol (HTTP) that provide a standard for editing and file management between computers on the Internet. By sending a specially crafted request to an IIS 5.0 server enabled WebDAV, a remote attacker may be able to execute arbitrary code in the Local System security context, essentially giving the attacker compete control of the system.
Another problem is a buffer overflow vulnerability in the function 'RtlGetFullPathName_U' which belongs to the 'ntdll.dll' and is called from some APIs or etc. As a result, if a local attacker made some programs or services that is able to call the 'RtlGetFullPathName_U' with a string which has the size over 65536 bytes, it is possible for him to execute arbitrary codes or escalate his privilege.
* Note: This check requires an account with Guest or upper privileges which can access the registry of the remote host to scan. Absence of these condition will result in the check not being performed and a False Negative for all vulnerable hosts.
* References:
http://www.microsoft.com/technet/security/bulletin/ms03-007.asp
http://www.cert.org/advisories/CA-2003-09.html
http://archives.neohapsis.com/archives/vulnwatch/2003-q1/0144.html
http://archives.neohapsis.com/archives/bugtraq/2003-06/0005.html
http://www.securityfocus.com/archive/1/323508
* Platforms Affected:
Microsoft IIS 5.0
Windows NT 4.0
Windows 2000 Any version
Windows XP Any version |
| Recommendation |
Apply the appropriate patch (Hotfix of 'Q815021') for your system, as listed in Microsoft Security Bulletin MS03-007, http://www.microsoft.com/technet/security/bulletin/ms03-007.asp
Workarounds:
If use of WebDAV is not required, disable it from the system. To disable WebDAV:
1. Use the IIS lockdown tool. This tool is available here:
http://www.microsoft.com/downloads/release.asp?ReleaseID=43955
2. Alternatively, you can disable WebDAV by following the instructions located in Microsoft's Knowledgebase Article 241520, "How to Disable WebDAV for IIS 5.0":
http://support.microsoft.com/default.aspx?scid=kb;en-us;241520
To completely disable WebDAV including the PUT and DELETE requests, make the following changes in the registry.
1) Start Registry Editor (Regedt32.exe).
2) Locate and click the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3SVC\Parameters
3) On the Edit menu, click Add Value, and then add the following registry value:
Value name: DisableWebDAV
Data type: DWORD
Value data: 1
3. You may also wish to use URLScan, which can block requests for 'PROPFIND' method. Information about URLScan is available at:
http://support.microsoft.com/default.aspx?scid=kb;[LN];326444
-- OR --
If you cannot use either IIS lockdown tool or URLScan, consider restricting the size of the buffer IIS utilizes to process requests by using Microsoft's URL Buffer Size Registry Tool. This tool can be run against a local or remote Windows 2000 system running Windows 2000 Service Pack 2 or Service Pack 3. The tool, instructions on how to use it, and instructions on how to manually make changes to the registry are available here:
URL Buffer Size Registry Tool - http://go.microsoft.com/fwlink/?LinkId=14875
Microsoft Knowledge Base Article 816930 - http://support.microsoft.com/default.aspx?scid=kb;en-us;816930
Microsoft Knowledge Base Article 260694 - http://support.microsoft.com/default.aspx?scid=kb;en-us;260694 |
| Related URL |
CVE-2003-0109 (CVE) |
| Related URL |
7116 (SecurityFocus) |
| Related URL |
11533 (ISS) |
|
