Security Group Not Used
- Query id: 4849211b-ac39-479e-ae78-5694d506cb24
- Query name: Security Group Not Used
- Platform: Terraform
- Severity: Info
- Category: Access Control
- URL: Github
Description¶
Security group must be used or not declared
Documentation
Code samples¶
Code samples with security vulnerabilities¶
Positive test num. 1 - tf file
resource "aws_lb" "test" {
name = "test"
load_balancer_type = "application"
subnets = [aws_subnet.subnet1.id, aws_subnet.subnet2.id]
internal = true
}
resource "aws_security_group" "allow_tls" {
name = "allow_tls"
description = "Allow TLS inbound traffic"
vpc_id = aws_vpc.main.id
ingress {
description = "TLS from VPC"
from_port = 443
to_port = 443
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
tags = {
Name = "allow_tls"
}
}
Positive test num. 2 - tf file
# given:
# - unused security group
# - aws_instance
# when:
# - no security group attached to aws_instance
# then:
# - detect unused security group as unused
resource "aws_instance" "positive1" {
ami = "ami-003634241a8fcdec0"
instance_type = "t2.micro"
}
resource "aws_security_group" "unused-sg" {
name = "unused-sg"
description = "Unused security group"
vpc_id = aws_vpc.main.id
ingress {
description = "Some port"
from_port = 42
to_port = 42
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
}
Positive test num. 3 - tf file
# given:
# - unused security group
# - used security group
# - aws_instance
# when:
# - used security group attached to aws_instance
# - unused security group not attached to aws_instance
# then:
# - detect only unused security group as unused
resource "aws_instance" "positive1" {
ami = "ami-003634241a8fcdec0"
instance_type = "t2.micro"
vpc_security_group_ids = [ aws_security_group.used_sg.id ]
}
resource "aws_security_group" "unused_sg" {
name = "unused-sg"
description = "Unused security group"
vpc_id = aws_vpc.main.id
ingress {
description = "Some port"
from_port = 42
to_port = 42
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
}
resource "aws_security_group" "used_sg" {
name = "used-sg"
description = "Used security group"
vpc_id = aws_vpc.main.id
ingress {
description = "Some port"
from_port = 43
to_port = 43
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
}
Positive test num. 4 - tf file
# given:
# - unused security group
# - used security group
# - aws_eks_cluster
# when:
# - used security group attached to aws_eks_cluster
# - unused security group not attached to aws_eks_cluster
# then:
# - detect only unused security group as unused
resource "aws_eks_cluster" "positive4" {
name = "beautiful-eks"
role_arn = aws_iam_role.example.arn
vpc_config {
security_group_ids = [ aws_security_group.used_sg.id ]
}
}
resource "aws_security_group" "unused_sg" {
name = "unused-sg"
description = "Unused security group"
vpc_id = aws_vpc.main.id
ingress {
description = "Some port"
from_port = 42
to_port = 42
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
}
resource "aws_security_group" "used_sg" {
name = "used-sg"
description = "Used security group"
vpc_id = aws_vpc.main.id
ingress {
description = "Some port"
from_port = 43
to_port = 43
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
}
Code samples without security vulnerabilities¶
Negative test num. 1 - tf file
resource "aws_security_group" "allow_tls" {
name = "allow_tls"
description = "Allow TLS inbound traffic"
vpc_id = aws_vpc.main.id
ingress {
description = "TLS from VPC"
from_port = 443
to_port = 443
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
tags = {
Name = "allow_tls"
}
}
resource "aws_lb" "test" {
name = "test"
load_balancer_type = "application"
subnets = [aws_subnet.subnet1.id, aws_subnet.subnet2.id]
internal = true
security_groups = [aws_security_group.allow_tls.id]
}
Negative test num. 2 - tf file
resource "aws_security_group" "allow_tls" {
name = "allow_tls"
description = "Allow TLS inbound traffic"
vpc_id = aws_vpc.main.id
ingress {
description = "TLS from VPC"
from_port = 443
to_port = 443
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
tags = {
Name = "allow_tls"
}
}
module "security_groups_test" {
source = "terraform-aws-modules/security-group/aws//modules/http-80"
version = "4.3.0"
name = "web-server"
security_group_id = aws_security_group.allow_tls.id
}
Negative test num. 3 - tf file
# given:
# - used security group
# - aws_instance
# when:
# - used security group attached to aws_instance
# then:
# - do not detect any unused security group
resource "aws_security_group" "used_sg" {
name = "used-sg"
description = "Used security group"
vpc_id = aws_vpc.main.id
ingress {
description = "Some port"
from_port = 43
to_port = 43
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
}
resource "aws_instance" "negative3" {
ami = "ami-003634241a8fcdec0"
instance_type = "t2.micro"
vpc_security_group_ids = [ "aws_security_group.used_sg.id" ]
}
Negative test num. 4 - tf file
terraform {
required_providers {
aws = {
source = "hashicorp/aws"
version = "~> 4.0"
}
}
required_version = ">= 1.1.0"
}
variable "iam_role" {
type = string
default = "AmazonSSMRoleForInstancesQuickSetup"
description = "Set AWS IAM role."
}
variable "ami_owner" {
type = string
default = "self"
description = "Set AWS image owner."
}
variable "region" {
type = string
default = "eu-west-3"
description = "Set AWS region."
}
variable "secgroups" {
type = list(string)
default = ["CowrieSSH"]
description = "Set AWS security groups."
}
data "aws_ami" "cowrie" {
most_recent = true
owners = ["var.ami_owner"]
filter {
name = "name"
values = ["cowrie-packer-*"]
}
filter {
name = "virtualization-type"
values = ["hvm"]
}
}
provider "aws" {
profile = "default"
region = var.region
}
resource "aws_security_group" "cowrie" {
name = "CowrieSSH"
description = "CowrieSSH Terraform security group"
ingress {
description = "Allow anyone to connect to the honeypot."
from_port = 22
to_port = 22
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
}
egress {
description = "Allow all outgoing traffic."
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
tags = {
Name = "cowrie_ssh_sg"
purpose = "honeypot"
}
}
resource "aws_instance" "cowrie_server" {
ami = data.aws_ami.cowrie.id
instance_type = "t3.nano"
security_groups = var.secgroups
iam_instance_profile = var.iam_role
metadata_options {
http_endpoint = "enabled"
http_tokens = "required"
}
tags = {
Name = "cowrie",
author = "foo"
vcs-url = "https://github.com/foo/bar"
purpose = "honeypot"
}
}
Negative test num. 5 - tf file
# given:
# - used security group
# - aws_eks_cluster
# when:
# - used security group attached to aws_eks_cluster
# then:
# - do not detect any unused security group
resource "aws_security_group" "used_sg" {
name = "used-sg"
description = "Used security group"
vpc_id = aws_vpc.main.id
ingress {
description = "Some port"
from_port = 43
to_port = 43
protocol = "tcp"
cidr_blocks = [aws_vpc.main.cidr_block]
ipv6_cidr_blocks = [aws_vpc.main.ipv6_cidr_block]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
ipv6_cidr_blocks = ["::/0"]
}
}
resource "aws_eks_cluster" "negative3" {
name = "beautiful-eks"
role_arn = aws_iam_role.example.arn
vpc_config {
security_group_ids = [ "aws_security_group.used_sg.id" ]
}
}