terraform.aws.security.aws-subnet-has-public-ip-address.aws-subnet-has-public-ip-address
semgrep
Author
unknown
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License
Resources in the AWS subnet are assigned a public IP address. Resources should not be exposed on the public internet, but should have access limited to consumers required for the function of your application. Set map_public_ip_on_launch
to false so that resources are not publicly-accessible.
Run Locally
Run in CI
Defintion
rules:
- id: aws-subnet-has-public-ip-address
patterns:
- pattern-either:
- pattern: |
resource "aws_subnet" $ANYTHING {
...
map_public_ip_on_launch = true
...
}
- pattern: |
resource "aws_default_subnet" $ANYTHING {
...
}
- pattern-not: |
resource "aws_default_subnet" $ANYTHING {
...
map_public_ip_on_launch = false
...
}
message: Resources in the AWS subnet are assigned a public IP address. Resources
should not be exposed on the public internet, but should have access
limited to consumers required for the function of your application. Set
`map_public_ip_on_launch` to false so that resources are not
publicly-accessible.
languages:
- hcl
severity: WARNING
metadata:
category: security
technology:
- terraform
- aws
owasp:
- A01:2021 - Broken Access Control
cwe:
- "CWE-284: Improper Access Control"
references:
- https://owasp.org/Top10/A01_2021-Broken_Access_Control/
- https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/subnet#map_public_ip_on_launch
- https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-instance-addressing.html#concepts-public-addresses
subcategory:
- audit
likelihood: LOW
impact: MEDIUM
confidence: MEDIUM
license: Commons Clause License Condition v1.0[LGPL-2.1-only]
vulnerability_class:
- Improper Authorization
Examples
aws-subnet-has-public-ip-address.tf
# ruleid: aws-subnet-has-public-ip-address
resource "aws_subnet" "fail_1" {
vpc_id = "vpc-123456"
map_public_ip_on_launch = true
}
# ruleid: aws-subnet-has-public-ip-address
resource "aws_default_subnet" "fail_2" {
availability_zone = "us-west-2a"
}
# ruleid: aws-subnet-has-public-ip-address
resource "aws_default_subnet" "fail_3" {
availability_zone = "us-west-2a"
map_public_ip_on_launch = true
}
# ok: aws-subnet-has-public-ip-address
resource "aws_subnet" "pass_1" {
vpc_id = "vpc-123456"
}
# ok: aws-subnet-has-public-ip-address
resource "aws_subnet" "pass_2" {
vpc_id = "vpc-123456"
map_public_ip_on_launch = false
}
# ok: aws-subnet-has-public-ip-address
resource "aws_default_subnet" "pass_3" {
availability_zone = "us-west-2a"
map_public_ip_on_launch = false
}
Short Link: https://sg.run/XJZw