search menu icon-carat-right cmu-wordmark

CERT Coordination Center

Reflection for Secure IT Windows Server can allow login to renamed built-in accounts

Vulnerability Note VU#902110

Original Release Date: 2005-08-31 | Last Revised: 2005-09-16

Overview

WRQ Reflection for Secure IT Windows Server 6.0 can allow a user to login to a Windows built-in account with the default name (Administrator and Guest) after they are renamed.

Description

Microsoft Windows includes the built-in accounts Administrator and Guest. If those accounts are renamed after SSH key authentication has been configured, the SSH keys associated with the account before the rename may continue to be accepted for authentication by Reflection for Secure IT Windows Server 6.0.

Impact

A malicious user can use the SSH keys of the account before the rename to gain authenticated access.

Solution

Workaround #1 (from WRQ):

Change the server configuration using the GUI as follows:

    1. Add the string 'administrator' (without the quotation marks) to the Deny login for users in User Restrictions.
    2. Create a subconfiguration entry in the Advanced screen by adding a UserSpecificConfig line to the end of the file, for example: "UserSpecificConfig  New-Admin-Name  admin.config"
    3. Click the Apply button to notify the running server of the changes.
    4. Create a file named admin.config in the folder where the server was installed (usually C:\Program Files\F-Secure\ssh server) that contains the following line:
    UserConfigDirectory "C:\Documents and Settings\administrator\.ssh2"

    Note: The doubled back slashes ( \ )are required. Both the sshd2_config and admin.config files should have their file protections changed to permit only the Administrator group to access to these files.

    Workaround #2 (from WRQ):

    Create a folder in the "Documents and Settings" folder with the renamed user name (such as, New-Admin-Name) and create an .ssh2 folder there (for example, C:\Documents and Settings\New-Admin-Name\.ssh2. Then move - do not copy - all public key files and the authorization file to this new folder.

    Remember to set the file protections on these folders to permit only the New-Admin-Name user access to these files.

    Vendor Information

    902110
     

    CVSS Metrics

    Group Score Vector
    Base
    Temporal
    Environmental

    References

    Acknowledgements

    Thanks to WRQ for reporting this issue.

    This document was written by Hal Burch.

    Other Information

    CVE IDs: None
    Severity Metric: 0.11
    Date Public: 2005-08-25
    Date First Published: 2005-08-31
    Date Last Updated: 2005-09-16 14:55 UTC
    Document Revision: 15

    Sponsored by CISA.