System objects: Strengthen default permissions of internal system objects (for example, Symbolic Links)
Applies to
- Windows 11
- Windows 10
Describes the best practices, location, values, policy management and security considerations for the System objects: Strengthen default permissions of internal system objects (e.g. Symbolic Links) security policy setting.
Reference
This policy setting determines the strength of the default discretionary access control list (DACL) for objects. Windows maintains a global list of shared system resources such as MS-DOS device names, mutexes, and semaphores. The processes use this list to locate and share objects. Each type of object is created with a default DACL that specifies who can access the objects with what permissions. Enabling this policy setting strengthens the default DACL and allows users who aren't administrators to read, but not to modify, shared objects that they didn't create.
Possible values
- Enabled
- Disabled
- Not defined
Best practices
- It's advisable to set this policy to Enabled.
Location
Computer Configuration\Windows Settings\Security Settings\ Local Policies\Security Options
Default values
The following table lists the actual and effective default values for this policy. 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 | Enabled |
| DC Effective Default Settings | Enabled |
| Member Server Effective Default Settings | Enabled |
| Client Computer Effective Default Settings | Enabled |
Policy management
This section describes features and tools that are available to help you manage this policy.
Restart requirement
None. Changes to this policy become effective without a device restart when they're saved locally or distributed through Group Policy.
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
This policy setting is enabled by default to protect against a known vulnerability that can be used with hard links or symbolic links. Hard links are actual directory entries in the file system. With hard links, the same data in a file system can be referred to by different file names. Symbolic links are text files that provide a pointer to the file that is interpreted and followed by the operating system as a path to another file or directory. Because symbolic links are a separate file, they can exist independently of the target location. If a symbolic link is deleted, its target location remains unaffected. When this setting is disabled, it's possible for a malicious user to destroy a data file by creating a link that looks like a temporary file that the system automatically creates, such as a sequentially named log file, but it points to the data file that the malicious user wants to eradicate. When the system writes the files with that name, the data is overwritten. Enabling System objects: Strengthen default permissions of internal system objects (e.g., Symbolic Links) prevents an attacker from exploiting programs that create files with predictable names by not allowing them to write to objects that they didn't create.
Countermeasure
Enable the System objects: Strengthen default permissions of global system objects (for example, Symbolic Links) setting.
Potential impact
None. This non-impact state is the default configuration.