Security Group With Unrestricted Access To SSH

• Query id: 65905cec-d691-4320-b320-2000436cb696
• Query name: Security Group With Unrestricted Access To SSH
• Platform: Terraform
• Severity: Medium
• Category: Networking and Firewall
• URL: Github

Description

'SSH' (TCP:22) should not be public in AWS Security Group
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

resource "aws_security_group" "positive1" {
  name        = "allow_tls"
  description = "Allow TLS inbound traffic"
  vpc_id      = aws_vpc.main.id

  ingress {
    description = "TLS from VPC"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "allow_tls"
  }
}

Positive test num. 2 - tf file

resource "aws_security_group" "positive2" {
  name        = "allow_tls"
  description = "Allow TLS inbound traffic"
  vpc_id      = aws_vpc.main.id

  ingress {
    description = "TLS from VPC"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["192.120.0.0/16", "0.0.0.0/0"]
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "allow_tls"
  }
}

Positive test num. 3 - tf file

module "vote_service_sg" {
  source = "terraform-aws-modules/security-group/aws"
  version = "4.3.0"
  name        = "user-service"
  description = "Security group for user-service with custom ports open within VPC, and PostgreSQL publicly open"
  vpc_id      = "vpc-12345678"

  ingress {
    description = "TLS from VPC"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "allow_tls"
  }
}

Positive test num. 4 - tf file

module "vote_service_sg" {
  source = "terraform-aws-modules/security-group/aws"
  version = "4.3.0"
  name        = "user-service"
  description = "Security group for user-service with custom ports open within VPC, and PostgreSQL publicly open"
  vpc_id      = "vpc-12345678"

  ingress {
    description = "TLS from VPC"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["192.120.0.0/16", "0.0.0.0/0"]
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "allow_tls"
  }
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

resource "aws_security_group" "negative1" {
  name        = "allow_tls"
  description = "Allow TLS inbound traffic"
  vpc_id      = aws_vpc.main.id

  ingress {
    description = "TLS from VPC"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["192.120.0.0/16", "75.132.0.0/16"]
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "allow_tls"
  }
}

Negative test num. 2 - tf file

module "vote_service_sg" {
  source = "terraform-aws-modules/security-group/aws"
  version = "4.3.0"
  name        = "user-service"
  description = "Security group for user-service with custom ports open within VPC, and PostgreSQL publicly open"
  vpc_id      = "vpc-12345678"

  ingress {
    description = "TLS from VPC"
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["192.120.0.0/16", "75.132.0.0/16"]
  }

  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  tags = {
    Name = "allow_tls"
  }
}