Create symbolic links

Applies To: Windows Vista, Windows Server 2008, Windows 7, Windows 8.1, Windows Server 2008 R2, Windows Server 2012 R2, Windows Server 2012, Windows 8

This security policy reference topic for the IT professional describes the best practices, location, values, policy management, and security considerations for this policy setting.

Reference

This user right determines if users can create a symbolic link from the computer they are logged on to.

A symbolic link is a file-system object that points to another file-system object. The object that is pointed to is called the target. Symbolic links are transparent to users. The links appear as normal files or directories, and they can be acted upon by the user or application in exactly the same manner. Symbolic links are designed to aid in migration and application compatibility with UNIX operating systems. Microsoft has implemented symbolic links to function just like UNIX links.

Warning This privilege should only be given to trusted users. Symbolic links can expose security vulnerabilities in applications that aren't designed to handle them.

This policy setting is supported on versions of Windows that are designated in the Applies To list at the beginning of this topic.

Constant: SeCreateSymbolicLinkPrivilege

Possible values

  • User-defined list of accounts

  • Not Defined

Best practices

  1. This user right should only be given to trusted users. Symbolic links can expose security vulnerabilities in applications that are not designed to handle them.

Location

GPO_name\Computer Configuration\Windows Settings\Security Settings\Local Policies\User Rights Assignment

Default values

By default, members of the Administrators group have this right.

The following table lists the actual and effective default policy values for the most recent supported versions of Windows. Default values are also listed on the policy’s property page.

Server type or GPO

Default value

Default Domain Policy

Not Defined

Default Domain Controller Policy

Not Defined

Stand-Alone Server Default Settings

Not Defined

Domain Controller Effective Default Settings

Administrators

Member Server Effective Default Settings

Administrators

Client Computer Effective Default Settings

Administrators

Operating system version differences

There are no differences in the way this policy setting works between the supported versions of Windows that are designated in the Applies To list at the beginning of this topic.

Policy management

This section describes different features and tools available to help you manage this policy.

A restart of the computer is not required for this policy setting to be effective.

Any change to the user rights assignment for an account becomes effective the next time the owner of the account logs on.

Group Policy

Settings are applied in the following order through a Group Policy Object (GPO), which will overwrite settings on the local computer at the next Group Policy update:

  1. Local policy settings

  2. Site policy settings

  3. Domain policy settings

  4. OU policy settings

When a local setting is greyed out, it indicates that a GPO currently controls that setting.

Command-line tools

This setting can be used in conjunction with a symbolic link file system setting that can be manipulated with the command-line tool to control the kinds of symlinks that are allowed on the computer. Type fsutil behavior set symlinkevalution /? at the command line to get more information about fsutil and symbolic links.

Security considerations

This section describes how an attacker might exploit a feature or its configuration, how to implement the countermeasure, and the possible negative consequences of countermeasure implementation.

Vulnerability

Users who have the Create symbolic links user right could inadvertently or maliciously expose your system to symbolic link attacks. Symbolic link attacks can be used to change the permissions on a file, to corrupt data, to destroy data, or as a DoS attack.

Countermeasure

Do not assign the Create symbolic links user right to standard users. Restrict this right to trusted administrators. You can use the fsutil command to establish a symbolic link file system setting that controls the kind of symbolic links that can be created on a computer.

Potential impact

None. Not defined is the default configuration.

See Also

User Rights Assignment