Unknown Port Exposed To Internet

• Query id: 590d878b-abdc-428f-895a-e2b68a0e1998
• Query name: Unknown Port Exposed To Internet
• Platform: Terraform
• Severity: High
• Category: Networking and Firewall
• CWE: 200
• Risk score: 7.1
• URL: Github

Description

AWS Security Group should not have an unknown port exposed to the entire Internet
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

resource "aws_security_group" "positive1-1" {
  name        = "allow_tls"
  description = "Unknown port exposed"

  ingress {
    description = "Unknown port exposed"
    from_port   = 44
    to_port     = 443
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

resource "aws_security_group" "positive1-2" {
  name        = "allow_tls"
  description = "Unknown port exposed"

  ingress {
    description = "Unknown port exposed"
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["192.168.0.0/24", "0.0.0.0/0"]
  }

  ingress {
    description = "Unknown port exposed"
    from_port   = 18
    to_port     = 18
    protocol    = "tcp"
    cidr_blocks = ["192.168.0.0/24", "0.0.0.0/0"]
  }
}

resource "aws_security_group" "positive1-3" {
  name        = "allow_tls"
  description = "Unknown port exposed"

  ingress {
    description = "Remote desktop open private"
    from_port   = 600
    to_port     = 1200
    protocol    = "tcp"
    ipv6_cidr_blocks = ["::/0"]
  }
}

resource "aws_security_group" "positive1-4" {
  name        = "allow_tls"
  description = "Unknown port exposed"

  ingress {
    description = "Unknown port exposed"
    from_port   = 60
    to_port     = 85
    protocol    = "tcp"
    ipv6_cidr_blocks = ["fd01::/8"]
  }

  ingress {
    description = "Unknown port exposed"
    from_port   = 65
    to_port     = 81
    protocol    = "tcp"
    ipv6_cidr_blocks = ["fd00::/8", "::/0"]
  }
}

resource "aws_security_group" "positive1-5" {
  name        = "allow_tls"
  description = "Unknown port exposed"

  ingress {
    description = "Unknown port exposed"
    from_port   = 5001
    to_port     = 5001
    protocol    = "tcp"
    cidr_blocks = ["192.120.0.0/16"]
    ipv6_cidr_blocks = ["::/0"]
  }
}

resource "aws_security_group" "positive1-6" {
  name        = "allow_tls"
  description = "Unknown port exposed"

  ingress {
    description = "Unknown port exposed"
    from_port   = 5001
    to_port     = 5001
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["fd00::/8"]
  }
}

resource "aws_security_group" "positive1-7" {
  name        = "allow_tls"
  description = "Unknown port exposed"

  ingress {
    description = "Unknown port exposed"
    from_port   = 5001
    to_port     = 5001
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }
}

Positive test num. 2 - tf file

resource "aws_security_group" "positive2" {
  name        = "allow_tls_1"
  description = "Allow TLS inbound traffic"
  vpc_id      = aws_vpc.main.id
}

resource "aws_vpc_security_group_ingress_rule" "positive2-1" {
  security_group_id = aws_security_group.positive2.id
  description       = "Unknown port exposed"

  cidr_ipv4         = "0.0.0.0/0"
  from_port         = 44
  to_port           = 443
  ip_protocol       = "tcp"
}

resource "aws_vpc_security_group_ingress_rule" "positive2-2" {
  security_group_id = aws_security_group.positive2.id
  description       = "Unknown port exposed"

  cidr_ipv6         = "::/0"
  from_port         = 600
  to_port           = 1200
  ip_protocol       = "tcp"
}

Positive test num. 3 - tf file

resource "aws_security_group" "positive3" {
  name        = "allow_tls_1"
  description = "Allow TLS inbound traffic"
  vpc_id      = aws_vpc.main.id
}

resource "aws_security_group_rule" "positive3-1" {
  type              = "ingress"
  security_group_id = aws_security_group.positive3.id
  description       = "Unknown port exposed"
  from_port         = 44
  to_port           = 443
  protocol          = "tcp"
  cidr_blocks       = ["0.0.0.0/0"]
}

resource "aws_security_group_rule" "positive3-2" {
  type              = "ingress"
  security_group_id = aws_security_group.positive3.id
  description       = "Unknown port exposed"
  from_port         = 600
  to_port           = 1200
  protocol          = "tcp"
  ipv6_cidr_blocks  = ["::/0"]
}

Positive test num. 4 - tf file

module "vote_service_sg_ipv4" {
  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_with_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 2300
      to_port     = 3000
      protocol    = "-1"
      cidr_blocks = ["10.92.168.0/28","0.0.0.0/0"]
    }
  ]
}

module "vote_service_sg_ipv4_array" {
  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_with_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 29000
      to_port     = 29000
      protocol    = "tcp"
      cidr_blocks = ["0.0.0.0/0", "1.2.3.4/27"]
    },
    {
      description = "TLS from VPC"
      from_port   = 28000
      to_port     = 28001
      protocol    = "tcp"
      cidr_blocks = ["10.0.0.0/8"]
    },
    {
      description = "TLS from VPC"
      from_port   = 2000
      to_port     = 2500
      protocol    = "tcp"
      cidr_blocks = ["0.0.0.0/0"]
    }
  ]
}

module "vote_service_sg_ipv6" {
  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_with_ipv6_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 2300
      to_port     = 3000
      protocol    = "tcp"
      ipv6_cidr_blocks = ["2001:0db8:85a3:0000:0000:8a2e:0370:7334/64","::/0"]
    }
  ]
}

module "vote_service_sg_ipv6_array" {
  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_with_ipv6_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 29000
      to_port     = 29000
      protocol    = "-1"
      ipv6_cidr_blocks = ["::/0","2606:4700:3033::6815:3e3/56"]
    },
    {
      description = "TLS from VPC"
      from_port   = 28000
      to_port     = 28001
      protocol    = "tcp"
      ipv6_cidr_blocks = ["2606:4700:3035::6815:3e3/24"]
    },
    {
      description = "TLS from VPC"
      from_port   = 2000
      to_port     = 2500
      protocol    = "tcp"
      ipv6_cidr_blocks = ["::/0"]
    }
  ]
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

resource "aws_security_group" "negative1-1" {

  ingress {
    description = "Remote desktop open private"
    from_port   = 2383
    to_port     = 2383
    protocol    = "tcp"
    cidr_blocks = ["192.168.0.0/24", "0.0.0.0/0"]
  }
}

resource "aws_security_group" "negative1-2" {

  ingress {
    description = "Remote desktop open private"
    from_port   = 20
    to_port     = 20
    protocol    = "tcp"
    ipv6_cidr_blocks = ["::/0"]
  }
}

resource "aws_security_group" "negative1-3" {

  ingress {
    description = "Remote desktop open private"
    from_port   = 0
    to_port     = 10000
    protocol    = "tcp"
    cidr_blocks = ["192.168.0.0/24", "192.201.0.0/12"]
  }
}

resource "aws_security_group" "negative1-4" {

  ingress {
    description = "Remote desktop open private"
    from_port   = 0
    to_port     = 10000
    protocol    = "tcp"
    ipv6_cidr_blocks = ["2001:db8:abcd:0012::/64"]
  }
}

Negative test num. 2 - tf file

resource "aws_security_group" "negative2" {
  name        = "allow_tls"
  description = "Allow TLS inbound traffic"
  vpc_id      = aws_vpc.main.id
}

resource "aws_vpc_security_group_ingress_rule" "negative2-1" {
  security_group_id = aws_security_group.negative3.id
  from_port         = 2383
  to_port           = 2383
  ip_protocol       = "tcp"
  cidr_ipv4         = "0.0.0.0/0"
  description       = "Remote desktop open private"
}


resource "aws_vpc_security_group_ingress_rule" "negative2-2" {
  security_group_id = aws_security_group.negative3.id
  from_port         = 20
  to_port           = 20
  ip_protocol       = "tcp"
  cidr_ipv6         = "::/0"
  description       = "Remote desktop open private"
}

resource "aws_vpc_security_group_ingress_rule" "negative2-3" {
  security_group_id = aws_security_group.negative3.id
  from_port         = 0
  to_port           = 10000
  ip_protocol       = "tcp"
  cidr_ipv4         = "192.168.0.0/24"
  description       = "Remote desktop open private"
}


resource "aws_vpc_security_group_ingress_rule" "negative2-4" {
  security_group_id = aws_security_group.negative3.id
  from_port         = 0
  to_port           = 10000
  ip_protocol       = "tcp"
  cidr_ipv6         = "2001:db8:abcd:0012::/64"
  description       = "Remote desktop open private"
}

Negative test num. 3 - tf file

resource "aws_security_group" "negative3" {
  name        = "allow_tls"
  description = "Allow TLS inbound traffic"
  vpc_id      = aws_vpc.main.id
}

resource "aws_security_group_rule" "negative3-1" {
  type              = "ingress"
  from_port         = 2383
  to_port           = 2383
  protocol          = "tcp"
  cidr_blocks       = ["192.168.0.0/24", "0.0.0.0/0"]
  security_group_id = aws_security_group.negative3.id
}

resource "aws_security_group_rule" "negative3-2" {
  type              = "ingress"
  from_port         = 20
  to_port           = 20
  protocol          = "tcp"
  ipv6_cidr_blocks  = ["::/0"]
  security_group_id = aws_security_group.negative3.id
}

resource "aws_security_group_rule" "negative3-3" {
  type              = "ingress"
  from_port         = 0
  to_port           = 10000
  protocol          = "tcp"
  cidr_blocks       = ["192.168.0.0/24", "192.162.0.0/24"]
  security_group_id = aws_security_group.negative3.id
}

resource "aws_security_group_rule" "negative3-4" {
  type              = "ingress"
  from_port         = 0
  to_port           = 10000
  protocol          = "tcp"
  ipv6_cidr_blocks  = ["2001:db8:abcd:0012::/64"]
  security_group_id = aws_security_group.negative3.id
}

Negative test num. 4 - tf file

module "vote_service_sg_ipv4" {
  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_with_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 0
      to_port     = 0
      protocol    = "-1"
      cidr_blocks = ["1.2.3.4"]
    }
  ]
}

module "vote_service_sg_ipv4_array" {
  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_with_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 2000
      to_port     = 2420
      protocol    = "udp"
      cidr_blocks = ["0.1.1.1/21", "8.8.8.8/24"]
    },
    {
      description = "TLS from VPC"
      from_port   = 28000
      to_port     = 28001
      protocol    = "tcp"
      cidr_blocks = ["2606:4700:3035::6815:3e3/24"]
    },
    {
      description = "TLS from VPC"
      from_port   = 22
      to_port     = 22
      protocol    = "tcp"
      cidr_blocks = ["192.01.01.02/23","0.0.0.0/0"]
    }
  ]
}

module "vote_service_sg_ipv6" {
  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_with_ipv6_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 0
      to_port     = 0
      protocol    = "tcp"
      ipv6_cidr_blocks = ["2001:0db8:85a3:0000:0000:8a2e:0370:7334/64"]
    }
  ]
}

module "vote_service_sg_ipv6_array" {
  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_with_ipv6_cidr_blocks = [
    {
      description = "TLS from VPC"
      from_port   = 2000
      to_port     = 2420
      protocol    = "udp"
      ipv6_cidr_blocks = ["2001:0db8:85a3::8a2e:0370:7334/64","2606:4700:3033::6815:3e3/56"]
    },
    {
      description = "TLS from VPC"
      from_port   = 28000
      to_port     = 28001
      protocol    = "tcp"
      ipv6_cidr_blocks = ["2606:4700:3035::6815:3e3/24"]
    },
    {
      description = "TLS from VPC"
      from_port   = 22
      to_port     = 22
      protocol    = "tcp"
      ipv6_cidr_blocks = ["::/0"]
    }
  ]
}