services / Azure / Virtual network gateway

An Azure Virtual Network Gateway provides VPN (site-to-site / point-to-site) and ExpressRoute connectivity between an Azure VNet and on-premises or remote networks. It is the production network ingress/egress edge for hybrid connectivity.

A gateway is the trust boundary for a single VNet's hybrid/remote connectivity; control of it can expose or sever access to an entire private network and its hosted services.

Microsoft.​Network/​virtualNetworkGateways/​listAllRadiusServersSecrets/​action

Returns the RADIUS server shared secrets used for VPN authentication, exposing reusable credential material that lets an attacker impersonate the gateway/RADIUS trust and pivot to the authentication backend.

Risks

1. Cryptographic exfiltration (CRITICAL)
2. Lateral movement (BOOST)

Scope: CRITICAL

This privilege may grant access to sensitive data from a significant fraction of organizational functions, allow interruption of critical organizational services, or its exploit could lead to significant privilege escalation.

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