services / Azure / Route table

A route table holds user-defined routes that override Azure's default system routes for the subnets it is associated with, controlling the next hop that traffic destined for given address prefixes takes.

A route table is a perimeter/segmentation control; it determines the path (and therefore the exposure) of a subnet's traffic. Rated consistent with the other network-segmentation resources documented alongside it, rather than CRITICAL, which is reserved for tenant-wide IAM/policy objects.

Microsoft.​Network/​routeTables/​join/​action

Azure requires this permission on the route table itself before a principal can associate a subnet with it, specifically so that a principal with only narrow "create resource" rights cannot silently reroute their own subnet's traffic away from mandated routing (e.g. through a firewall/NVA). Holding join lets an attacker associate an attacker-controlled or victim subnet with a route table that redirects traffic to an attacker-chosen next hop, bypassing intended routing/segmentation control.

Risks

1. Network movement (BOOST)

Scope: HIGH

This privilege may grant access to sensitive data from a single organizational function, or allow interruption of a service supporting a single organizational function.

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