| VID |
28058 |
| Severity |
40 |
| Port |
139,445 |
| Protocol |
TCP |
| Class |
SMB |
| Detailed Description |
The 'RAS' registry key is writable by users who are not in the Administrators group. The location of the RAS registry key is HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RAS.
The registry key in Windows NT 4.0 that handles the administration of Remote Access Service (RAS) third-party tools is not properly configured to deny write access to unprivileged users. Such lenient permissions assigned to this particular registry key would allow any user that could log on locally to a system with a RAS server installed to modify the value of the key to an arbitrary DLL file that would be executed upon startup of RAS.
The DLL in the RAS registry key is run under LocalSystem privileges. Therefore, the malicious user would be able to perform any action under the LocalSystem security context which would basically yield full control over the local machine. This vulnerability could be exploited remotely if the Winreg key was enabled to allow remote access to the registry (Winreg is disabled by default in Windows NT Server and enabled by default in Windows NT Workstation).
RAS is not installed by default on Windows NT 4.0.
* 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/MS00-095.asp
http://www.ciac.org/ciac/bulletins/l-026.shtml
* Platforms Affected:
Windows NT Any version |
| Recommendation |
Apply the patch for your system, as listed in Microsoft Security Bulletin MS00-095 at http://www.microsoft.com/technet/security/bulletin/MS00-095.asp
-- OR --
Remove write access to the RAS registry key from users who are not in the Administrators group. This requires a modification in the registry as the following steps:
1. Open Registry Editor. From the Windows NT Start menu, select Run, type regedt32, and click OK.
2. Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\RAS.
3. From the Security menu, select Permissions to display the Registry Key Permissions dialog box.
4. Remove or change any permissions such as Everyone - Full Control. And review any names with Full Control permissions and determine if the permission is appropriate. Originally, This registry key is set as the following permissions:
- Administrators group : Full Control
- SYSTEM : Full Control
- Everyone : Read |
| Related URL |
CVE-2001-0045 (CVE) |
| Related URL |
2064 (SecurityFocus) |
| Related URL |
5671 (ISS) |
|
