SMB share writable by Everyone

everyone-writable-netbios-share (19) The risk level is classified as MediumMedium Risk

Description:

An SMB share has been detected, which allows anyone to access the computer and to write to the share. In some cases, an attacker can use these shares to gain access to the entire hard disk.


Consequences:

Gain Access

Remedy:

Remove write access from unapproved users.

  1. From the local computer, open Windows NT Explorer.
  2. Navigate to the shared folder.
  3. Right-click the shared folder name and select Sharing to display the Properties dialog box.
  4. Click Permissions.
  5. Use these guidelines to review the listed permissions:
    • Remove or change any permissions such as Everyone: Full Control. This default permission allows all users to read, modify, and even change ownership and permissions on the items in the share.
    • Review any names with Change or Full Control permissions and determine if the permission is appropriate. Consider using Read Only or No Access if these names do not need to modify items in the share.
    • Review any names that should not be in the list, and remove the name or change their permission as appropriate.

— OR —

Remove the share using one of the following options:

  • Remove the share from a local computer.

    1. From the local computer, open Windows NT Explorer.
    2. Navigate to the shared folder.
    3. Right-click the shared folder name and select Sharing to display the Properties dialog box.
    4. To disallow access to all users, select the Not Shared check box.
    5. Click OK.

  • Remove the share from a remote computer.

    1. From a remote computer, open the Server Manager.
    2. Select the host name.
    3. From the Computer menu, choose Shared Directories to display the Shared Directories dialog box.
    4. Select the SMB share
    5. Click Stop Sharing.
    6. Click OK.

  • Remove the share from the command line. From a command prompt, type: net share sharename/delete

    • References:

    • CVE-1999-0519: A NETBIOS/SMB share password is the default, null, or missing.
    • CVE-1999-0520: A system-critical NETBIOS/SMB share has inappropriate access control.

    Platforms Affected:

    • Microsoft Windows 2000
    • Microsoft Windows 2003 Server
    • Microsoft Windows 95
    • Microsoft Windows 98
    • Microsoft Windows 98SE
    • Microsoft Windows Me
    • Microsoft Windows NT 4.0
    • Microsoft Windows XP

    Reported:

    Not available

    The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

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