Security Group Rule Without Description

• Query id: 68eb4bf3-f9bf-463d-b5cf-e029bb446d2e
• Query name: Security Group Rule Without Description
• Platform: Terraform
• Severity: Info
• Category: Best Practices
• URL: Github

Description

It's considered a best practice for all rules in AWS Security Group to have a description
Documentation

Code samples

Code samples with security vulnerabilities

Positive 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 {
    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

resource "aws_security_group" "positive2" { 

  name        = "${var.prefix}-external-http-https"
  description = "Allow main HTTP / HTTPS"
  vpc_id      = local.vpc_id

  ingress {
    description = "Enable HTTP access for select VMs"
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  ingress {
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "${var.prefix}-external-http-https"
  }
}

Positive test num. 3 - tf file

resource "aws_security_group" "positive3" {

  name        = "${var.prefix}-external-http-https"
  description = "Allow main HTTP / HTTPS"
  vpc_id      = local.vpc_id

  tags = {
    Name = "${var.prefix}-external-http-https"
  }
}

resource "aws_security_group_rule" "positive3a" {

  description       = "Enable HTTP access for select VMs"
  from_port         = 80
  to_port           = 80
  cidr_blocks       = ["0.0.0.0/0"]
  protocol          = "tcp"
  security_group_id = aws_security_group.positive3.id
  type              = "ingress"
}

resource "aws_security_group_rule" "positive3b" {

  from_port         = 443
  to_port           = 443
  cidr_blocks       = ["0.0.0.0/0"]
  protocol          = "tcp"
  security_group_id = aws_security_group.positive3.id
  type              = "ingress"
}

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]
  }

  tags = {
    Name = "allow_tls"
  }
}

Negative test num. 2 - tf file

resource "aws_security_group" "negative2" {

  name        = "${var.prefix}-external-http-https"
  description = "Allow main HTTP / HTTPS"
  vpc_id      = local.vpc_id

  ingress {
    description = "Enable HTTP access for select VMs"
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  ingress {
    description = "Enable HTTPS access for select VMs"
    from_port   = 443
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "${var.prefix}-external-http-https"
  }
}

Negative test num. 3 - tf file

resource "aws_security_group" "negative3" {

  name        = "${var.prefix}-external-http-https"
  description = "Allow main HTTP / HTTPS"
  vpc_id      = local.vpc_id

  tags = {
    Name = "${var.prefix}-external-http-https"
  }
}

resource "aws_security_group_rule" "negative3a" {

  from_port         = 80
  to_port           = 80
  protocol          = "tcp"
  cidr_blocks       = ["0.0.0.0/0"]
  security_group_id = aws_security_group.negative3.id
  type              = "ingress"
  description       = "Enable HTTP access for select VMs"
}

resource "aws_security_group_rule" "negative3b" {

  from_port         = 443
  to_port           = 443
  protocol          = "tcp"
  cidr_blocks       = ["0.0.0.0/0"]
  security_group_id = aws_security_group.negative3.id
  type              = "ingress"
  description       = "Enable HTTPS access for select VMs"
}