Harden your Cluster Against IdP Compromises

This guide aims to help you fortify your identity infrastructure and mitigate the risks associated with IdP weaknesses.

An IdP compromise occurs when an attacker gains unauthorized access to your identity management system, potentially allowing them to impersonate legitimate users, escalate privileges, or access sensitive information. This can happen through various means, such as exploiting software vulnerabilities, stealing credentials, or social engineering attacks.

While many organizations have implemented basic security measures like single sign-on (SSO) and multi-factor authentication (MFA), these alone may not be sufficient to protect against sophisticated attacks targeting your IdP. Attackers are constantly evolving their techniques, and traditional security measures may have limitations or vulnerabilities that can be exploited.

To enhance your defense against IdP compromises, we recommend implementing the following comprehensive security measures.

Set up cluster-wide WebAuthn

Implement strong, phishing-resistant authentication across your entire infrastructure using WebAuthn standards. WebAuthn, a W3C standard and part of FIDO2, enables public-key cryptography for web authentication. Teleport supports WebAuthn as a multi-factor for logging into Teleport (via tsh login or Web UI) and accessing SSH nodes or Kubernetes clusters. It's compatible with hardware keys (e.g., YubiKeys, SoloKeys) and biometric authenticators like Touch ID and Windows Hello.

Prerequisites

• A running Teleport cluster or Teleport Cloud, version 16 or later. If you want to get started with Teleport, sign up for a free trial.

• The tctl admin tool and tsh client tool.

  Visit Installation for instructions on downloading tctl and tsh.

• WebAuthn hardware device, such as YubiKey or SoloKey

• A Web browser with WebAuthn support

• To check that you can connect to your Teleport cluster, sign in with tsh login, then verify that you can run tctl commands using your current credentials.

  For example:

  tsh login --proxy=teleport.example.com --user=email@example.com
  tctl status
  Cluster  teleport.example.com
  Version  17.0.1
  CA pin   sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678

  If you can connect to the cluster and run the tctl status command, you can use your current credentials to run subsequent tctl commands from your workstation. If you host your own Teleport cluster, you can also run tctl commands on the computer that hosts the Teleport Auth Service for full permissions.

Step 1/3. Enable WebAuthn support

WebAuthn is disabled by default. To enable WebAuthn support, update your Teleport configuration as below:

Edit the cluster_auth_preference resource:

tctl edit cap

Update the cluster_auth_preference definition to include the following content:

kind: cluster_auth_preference
version: v2
metadata:
  name: cluster-auth-preference
spec:
  type: local
  # To enable WebAuthn support, set this field to 'on', 'optional' or 'webauthn'
  second_factor: "on"
  webauthn:
    # Required, replace with proxy web address (example.com, example.teleport.sh).
    # rp_id is the public domain of the Teleport Proxy Service, *excluding* protocol
    # (https://) and port number.
    rp_id: example.com
    # Optional, attestation_allowed_cas is an optional allow list
    # of certificate authorities.
    attestation_allowed_cas:
    # Entries can be paths to certificate files:
    - "/path/to/allowed_ca.pem"
    # Entries can also be inline certificates:
    - |
      -----BEGIN CERTIFICATE-----
      ...
      -----END CERTIFICATE-----
    # Optional, attestation_denied_cas is an optional deny list
    # of certificate authorities.
    attestation_denied_cas:
    # Entries can be paths to certificate files:
    - "/path/to/denied_ca.pem"
    # Entries can also be inline certificates:
    - |
      -----BEGIN CERTIFICATE-----
      ...
      -----END CERTIFICATE-----

Save and exit the file. tctl will update the remote definition:

cluster auth preference has been updated

webauthn fields definitions

rp_id is the public domain of the Teleport Proxy Service, excluding protocol (https://) and port number.

attestation_allowed_cas is an optional allow list of certificate authorities (as local file paths or inline PEM certificate strings) for device verification.

This field allows you to restrict which device models and vendors you trust. Devices outside of the list will be rejected during registration. By default all devices are allowed. If you must use attestation, consider using attestation_denied_cas to forbid troublesome devices instead.

attestation_denied_cas is an optional deny list of certificate authorities (as local file paths or inline PEM certificate strings) for device verification.

This field allows you to forbid specific device models and vendors, while allowing all others (provided they clear attestation_allowed_cas as well). Devices within this list will be rejected during registration. By default no devices are forbidden.

Step 2/3. Register WebAuthn devices as a user

A user can register multiple WebAuthn devices using tsh:

tsh mfa add
Choose device type [TOTP, WEBAUTHN]: webauthn
Enter device name: desktop yubikey
Tap any *registered* security key or enter a code from a *registered* OTP device:
Tap your *new* security key
MFA device "desktop yubikey" added.

Step 3/3. Log in using WebAuthn

Once a WebAuthn device is registered, the user will be prompted for it on login:

tsh login --proxy=example.teleport.sh
Enter password for Teleport user codingllama:
Tap any security key or enter a code from a OTP device:
> Profile URL:        https://example.teleport.sh
Logged in as:       codingllama
Cluster:            example.teleport.sh
Roles:              access, editor, reviewer
Logins:             codingllama
Kubernetes:         enabled
Valid until:        2021-10-04 23:32:29 -0700 PDT [valid for 12h0m0s]
Extensions:         permit-agent-forwarding, permit-port-forwarding, permit-pty

Configure per-session MFA

Ensure that multi-factor authentication is required for each session, not just at initial login, to maintain continuous security. Teleport's per-session MFA enhances security by protecting against compromised on-disk certificates. It requires additional MFA checks when initiating new SSH, Kubernetes, database, or desktop sessions.

Teleport supports requiring additional multi-factor authentication checks when starting new:

• SSH connections (a single tsh ssh call, Web UI SSH session or Teleport Connect SSH session)
• Kubernetes sessions (a single kubectl call)
• Database sessions (a single tsh db connect call)
• Application sessions
• Desktop sessions

To enforce MFA checks for all roles, edit your cluster authentication configuration:

Edit your cluster_auth_preference resource:

tctl edit cap

Ensure that the resource contains the following content:

kind: cluster_auth_preference
metadata:
  name: cluster-auth-preference
spec:
  require_session_mfa: true
version: v2

Save and close the file in your editor to apply your changes.

Per role

To enforce MFA checks for a specific role, update the role to contain:

kind: role
version: v7
metadata:
  name: example-role-with-mfa
spec:
  options:
    # require per-session MFA for this role
    require_session_mfa: true
  allow:
    ...
  deny:
    ...

Implement cluster-wide Device Trust

Develop a system to verify and manage trusted devices across your organization, reducing the risk of unauthorized access from unknown or compromised devices. Device Trust adds an extra layer of security by requiring the use of trusted devices for accessing protected resources, complementing user identity and role enforcement. This can be configured cluster-wide or via RBAC. Supported resources include apps (role-based only), SSH nodes, databases, Kubernetes clusters, and first MFA device enrollment. The latter helps prevent auto-provisioning of new users through compromised IdPs.

Prerequisites

• To enroll a macOS device, you need:
  • A signed and notarized tsh binary. Download the macOS tsh installer.
• To enroll a Windows device, you need:
  • A device with TPM 2.0.
  • A user with administrator privileges. This is only required during enrollment.
  • tsh v13.1.2 or newer. Download the Windows tsh installer.
• To enroll a Linux device, you need:
  • A device with TPM 2.0.
  • A user with permissions to use the /dev/tpmrm0 device (typically done by assigning the tss group to the user).
  • tsh v15.0.0 or newer. Install tsh for Linux.
• To authenticate a Web UI session you need Teleport Connect

The tctl tool is used to manage the device inventory. A device admin is responsible for managing devices, adding new devices to the inventory and removing devices that are no longer in use.

tsh device enroll --current-device

Step 1/3. Register a trusted device

Before you can enroll the device, you need to register it. To register a device, you first need to determine its serial number.

Retrieve device serial number with tsh (must be run on the device you want to register):

tsh device asset-tag
C00AA0AAAA0A

tsh device asset-tag
C00AA0AAAA0A

Replace C00AA0AAAA0A with the serial number of the device you wish to enroll and run the tctl devices add command:

tctl devices add --os='macos' --asset-tag='C00AA0AAAA0A'
Device C00AA0AAAA0A/macos added to the inventory

Use tctl to check that the device has been registered:

tctl devices ls
Asset Tag    OS    Enroll Status Device ID------------ ----- ------------- ------------------------------------C00AA0AAAA0A macOS not enrolled  9cdfc0ad-64b7-4d9c-this-is-an-example

Step 2/3. Create a device enrollment token

A registered device becomes a trusted device after it goes through the enrollment ceremony. To enroll the device, a device enrollment token is necessary. The token is created by a device admin and sent to the person performing the enrollment off-band (for example, via a corporate chat).

To create an enrollment token run the command below, where --asset-tag is the serial number of the device we want to enroll:

tctl devices enroll --asset-tag="C00AA0AAAA0A"
Run the command below on device "C00AA0AAAA0A" to enroll it:tsh device enroll --token=AAAAAAAAAAAAAAAAAAAAAAAA-this-is-an-example

Step 3/3. Enroll a trusted device

To perform the enrollment ceremony, using the device specified above, type the command printed by tctl devices enroll:

tsh device enroll --token=AAAAAAAAAAAAAAAAAAAAAAAA-this-is-an-example
Device "C00AA0AAAA0A"/macOS enrolled
tsh logout
tsh login --proxy=teleport.example.com --user=myuser # fetch new certificates
Enter password for Teleport user myuser:Tap any security keyDetected security key tap> Profile URL:        teleport.example.com:443  Logged in as:       myuser  Cluster:            teleport.example.com  Roles:              access, editor  Logins:             myuser  Kubernetes:         enabled  Valid until:        2023-06-23 02:47:05 -0300 -03 [valid for 12h0m0s]  Extensions:         teleport-device-asset-tag, teleport-device-credential-id, teleport-device-id

The presence of the teleport-device-* extensions shows that the device was successfully enrolled and authenticated. The device above is now a trusted device.

Auto-Enrollment

Distributing enrollment tokens to many users can be challenging. To address that, Teleport supports auto-enrollment. When enabled, auto-enrollment automatically enrolls the user's device in their next Teleport (tsh) login.

For auto-enrollment to work, the following conditions must be met:

• A device must be registered. Registration may be manual or performed using an integration, like the Jamf Pro integration.
• Auto-enrollment must be enabled in the cluster setting.

Step 1/2. Enable auto-enrollment in your cluster settings

Modify the dynamic config resource using tctl edit cluster_auth_preference:

kind: cluster_auth_preference
version: v2
metadata:
  name: cluster-auth-preference
spec:
  # ...
  device_trust:
    mode: "required"
+   auto_enroll: true

Step 2/2. Log out and back in

Once enabled, users with their device registered in Teleport will have their device enrolled to Teleport in their next login.

tsh logout
All users logged out.
tsh login --proxy=teleport.example.com --user=myuser
Enter password for Teleport user myuser:Tap any security keyDetected security key tap> Profile URL:        teleport.example.com:443  Logged in as:       myuser  Cluster:            teleport.example.com  Roles:              access, editor  Logins:             myuser  Kubernetes:         enabled  Valid until:        2023-06-23 02:47:05 -0300 -03 [valid for 12h0m0s]  Extensions:         teleport-device-asset-tag, teleport-device-credential-id, teleport-device-id

The presence of the teleport-device-* extensions shows that the device was successfully enrolled and authenticated.

Require MFA for administrative actions

Add an extra layer of security for sensitive administrative operations by requiring multi-factor authentication for these high-privilege actions. Teleport enforces additional MFA verification for administrative actions across all clients (tctl, tsh, Web UI, and Connect). This feature adds an extra security layer by re-verifying user identity immediately before any admin action, mitigating risks from compromised admin accounts.

By adopting these advanced security measures, you can create a robust defense against IdP compromises and significantly reduce your organization's attack surface. In the following sections, we'll dive deeper into each of these recommendations, providing step-by-step guidance on implementation and best practices.

Prerequisites

• To check that you can connect to your Teleport cluster, sign in with tsh login, then verify that you can run tctl commands using your current credentials. For example:

  tsh login --proxy=teleport.example.com --user=email@example.com
  tctl status
  Cluster  teleport.example.com
  Version  17.0.1
  CA pin   sha256:abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678abdc1245efgh5678

  If you can connect to the cluster and run the tctl status command, you can use your current credentials to run subsequent tctl commands from your workstation. If you host your own Teleport cluster, you can also run tctl commands on the computer that hosts the Teleport Auth Service for full permissions.
• WebAuthn configured on this cluster
• Multi-factor hardware device, such as YubiKey or SoloKey
• A Web browser with WebAuthn support (if using SSH or desktop sessions from the Teleport Web UI).

MFA for administrative actions is automatically enforced for clusters where WebAuthn is the only form of multi-factor allowed.

Examples of administrative actions include, but are not limited to:

• Resetting or recovering user accounts
• Inviting new users
• Updating cluster configuration resources
• Modifying access management resources
• Approving Access Requests
• Generating new join tokens
• Impersonation
• Creating new bots for Machine ID

This is an advanced security feature that protects users against compromises of their on-disk Teleport certificates.

Step 1/2. Edit the resource

Edit the cluster_auth_preference resource:

tctl edit cap

Update the cluster_auth_preference definition to include the following content:

kind: cluster_auth_preference
version: v2
metadata:
  name: cluster-auth-preference
spec:
  type: local
  # To make webauthn the only form of multi-factor allowed, set this field to 'webauthn'.
  second_factor: "webauthn"
  webauthn:
    rp_id: example.com

Step 2/2. Save and exit the file

The command tctl will update the remote definition:

cluster auth preference has been updated

Next steps

For additional cluster hardening measures, see:

• Passwordless Authentication: Provides passwordless and usernameless authentication.
• Locking: Lock access to active user sessions or hosts.
• Moderated Sessions: Require session auditors and allow fine-grained live session access.
• Hardware Key Support: Enforce the use of hardware-based private keys.