Ensure routing tables for VPC peering are "least access"

MediumLevel 1Manual reviewalibaba

Description

Once a VPC peering connection is established, routing tables must be updated to establish any connections between the peered VPCs. These routes can be as specific as desired, even peering a VPC to only a single host on the other side of the connection. Although the routing table is empty by default upon creation for any newly created routing table, hence it denies any default access, it is recommended that the table entry is only added based on the least access ... Reported as a manual review item: the benchmark audit needs console review or organisational judgement.

How it is checked

Audit method: Manual review

This recommendation cannot be checked automatically. A scan lists it with these instructions when you pass --include-manual.

1. Logon to VPC console. 2. Open the routing table 3. Review routing tables of peered VPCs for whether they route all subnets of each VPC and whether that is necessary to accomplish the intended purposes for peering the VPCs.

How it is fixed

Fix method: Guidance or infrastructure patch

1. Logon to VPC console. 2. Open the routing table 3. Remove and add route table entries to ensure that the least number of subnets or hosts as is required to accomplish the purpose for peering are routable.

Properties

Operating systems: Any
Tags: alibabanetwork
Reference: CIS Alibaba Cloud Foundation Benchmark v2.0.1 - 3.4 Ensure routing tables for VPC peering are "least access"