deny-assignments.md

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Understand Azure deny assignments - Azure RBAC	Learn about Azure deny assignments in Azure role-based access control (Azure RBAC).	active-directory		rolyon	karenhoran		role-based-access-control	conceptual	na	identity	03/25/2022	rolyon	bagovind

Understand Azure deny assignments

Similar to a role assignment, a deny assignment attaches a set of deny actions to a user, group, or service principal at a particular scope for the purpose of denying access. Deny assignments block users from performing specific Azure resource actions even if a role assignment grants them access.

This article describes how deny assignments are defined.

How deny assignments are created

Deny assignments are created and managed by Azure to protect resources. Azure Blueprints and Azure managed apps use deny assignments to protect system-managed resources. Azure Blueprints and Azure managed apps are the only way that deny assignments are used within Azure. You can't directly create your own deny assignments. Azure Blueprints uses deny assignments to lock resources, but just for resources deployed as part of a blueprint. For more information, see Understand resource locking in Azure Blueprints.

Note

You can't directly create your own deny assignments.

Compare role assignments and deny assignments

Deny assignments follow a similar pattern as role assignments, but also have some differences.

Capability	Role assignment	Deny assignment
Grant access	✔️
Deny access		✔️
Can be directly created	✔️
Apply at a scope	✔️	✔️
Exclude principals		✔️
Prevent inheritance to child scopes		✔️
Apply to classic subscription administrator assignments		✔️

Deny assignment properties

A deny assignment has the following properties:

[!div class="mx-tableFixed"]

Property	Required	Type	Description
DenyAssignmentName	Yes	String	The display name of the deny assignment. Names must be unique for a given scope.
Description	No	String	The description of the deny assignment.
Permissions.Actions	At least one Actions or one DataActions	String[]	An array of strings that specify the control plane actions to which the deny assignment blocks access.
Permissions.NotActions	No	String[]	An array of strings that specify the control plane action to exclude from the deny assignment.
Permissions.DataActions	At least one Actions or one DataActions	String[]	An array of strings that specify the data plane actions to which the deny assignment blocks access.
Permissions.NotDataActions	No	String[]	An array of strings that specify the data plane actions to exclude from the deny assignment.
Scope	No	String	A string that specifies the scope that the deny assignment applies to.
DoNotApplyToChildScopes	No	Boolean	Specifies whether the deny assignment applies to child scopes. Default value is false.
Principals[i].Id	Yes	String[]	An array of Azure AD principal object IDs (user, group, service principal, or managed identity) to which the deny assignment applies. Set to an empty GUID 00000000-0000-0000-0000-000000000000 to represent all principals.
Principals[i].Type	No	String[]	An array of object types represented by Principals[i].Id. Set to SystemDefined to represent all principals.
ExcludePrincipals[i].Id	No	String[]	An array of Azure AD principal object IDs (user, group, service principal, or managed identity) to which the deny assignment does not apply.
ExcludePrincipals[i].Type	No	String[]	An array of object types represented by ExcludePrincipals[i].Id.
IsSystemProtected	No	Boolean	Specifies whether this deny assignment was created by Azure and cannot be edited or deleted. Currently, all deny assignments are system protected.

The All Principals principal

To support deny assignments, a system-defined principal named All Principals has been introduced. This principal represents all users, groups, service principals, and managed identities in an Azure AD directory. If the principal ID is a zero GUID 00000000-0000-0000-0000-000000000000 and the principal type is SystemDefined, the principal represents all principals. In Azure PowerShell output, All Principals looks like the following:

Principals              : {
                          DisplayName:  All Principals
                          ObjectType:   SystemDefined
                          ObjectId:     00000000-0000-0000-0000-000000000000
                          }

All Principals can be combined with ExcludePrincipals to deny all principals except some users. All Principals has the following constraints:

• Can be used only in Principals and cannot be used in ExcludePrincipals.
• Principals[i].Type must be set to SystemDefined.

Next steps

• List Azure deny assignments using the Azure portal