ELB Using Weak Ciphers

• Query id: 4a800e14-c94a-442d-9067-5a2e9f6c0a4c
• Query name: ELB Using Weak Ciphers
• Platform: Terraform
• Severity: High
• Category: Encryption
• CWE: 326
• URL: Github

Description

ELB Predefined or Custom Security Policies must not use weak ciphers, to reduce the risk of the SSL connection between the client and the load balancer being exploited. That means the 'name' of 'policy_attributes' must not coincide with any of a predefined list of weak ciphers.
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

#this is a problematic code where the query should report a result(s)
resource "aws_elb" "positive1" {
  name               = "wu-tang"
  availability_zones = ["us-east-1a"]

  listener {
    instance_port      = 443
    instance_protocol  = "http"
    lb_port            = 443
    lb_protocol        = "https"
    ssl_certificate_id = "arn:aws:iam::000000000000:server-certificate/wu-tang.net"
  }

  tags = {
    Name = "wu-tang"
  }
}

resource "aws_load_balancer_policy" "positive2" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ca-pubkey-policy"
  policy_type_name   = "PublicKeyPolicyType"

  policy_attribute {
    name  = "PublicKey"
    value = file("wu-tang-pubkey")
  }
}

resource "aws_load_balancer_policy" "positive3" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-root-ca-backend-auth-policy"
  policy_type_name   = "BackendServerAuthenticationPolicyType"

  policy_attribute {
    name  = "PublicKeyPolicyName"
    value = aws_load_balancer_policy.wu-tang-root-ca-pubkey-policy.policy_name
  }
}

resource "aws_load_balancer_policy" "positive4" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ssl"
  policy_type_name   = "SSLNegotiationPolicyType"

  policy_attribute {
    name  = "Protocol-TLSv1.2"
    value = "true"
  }

  policy_attribute {
    name  = "TLS_RSA_ARCFOUR_128_SHA1"
    value = "true"
  }
}

resource "aws_load_balancer_policy" "positive5" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ssl"
  policy_type_name   = "SSLNegotiationPolicyType"

  policy_attribute {
    name  = "DES-CBC3-SHA"
    value = "true"
  }
}

resource "aws_load_balancer_policy" "positive6" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ssl"
  policy_type_name   = "SSLNegotiationPolicyType"

  policy_attribute {
    name  = "TLS_ECDHE_ECDSA_WITH_ARIA_256_GCM_SHA384"
    value = "true"
  }
}

resource "aws_load_balancer_policy" "positive7" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ssl"
  policy_type_name   = "SSLNegotiationPolicyType"

  policy_attribute {
    name  = "Reference-Security-Policy"
    value = "ELBSecurityPolicy-TLS-1-1-2017-01"
  }
}

resource "aws_load_balancer_backend_server_policy" "positive8" {
  load_balancer_name = aws_elb.wu-tang.name
  instance_port      = 443

  policy_names = [
    aws_load_balancer_policy.wu-tang-root-ca-backend-auth-policy.policy_name,
  ]
}

resource "aws_load_balancer_listener_policy" "positive9" {
  load_balancer_name = aws_elb.wu-tang.name
  load_balancer_port = 443

  policy_names = [
    aws_load_balancer_policy.wu-tang-ssl.policy_name,
  ]
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

#this code is a correct code for which the query should not find any result
resource "aws_elb" "negative1" {
  name               = "wu-tang"
  availability_zones = ["us-east-1a"]

  listener {
    instance_port      = 443
    instance_protocol  = "http"
    lb_port            = 443
    lb_protocol        = "https"
    ssl_certificate_id = "arn:aws:iam::000000000000:server-certificate/wu-tang.net"
  }

  tags = {
    Name = "wu-tang"
  }
}

resource "aws_load_balancer_policy" "negative2" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ca-pubkey-policy"
  policy_type_name   = "PublicKeyPolicyType"

  policy_attribute {
    name  = "PublicKey"
    value = file("wu-tang-pubkey")
  }
}

resource "aws_load_balancer_policy" "negative3" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-root-ca-backend-auth-policy"
  policy_type_name   = "BackendServerAuthenticationPolicyType"

  policy_attribute {
    name  = "PublicKeyPolicyName"
    value = aws_load_balancer_policy.wu-tang-root-ca-pubkey-policy.policy_name
  }
}

resource "aws_load_balancer_policy" "negative4" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ssl"
  policy_type_name   = "SSLNegotiationPolicyType"

  policy_attribute {
    name  = "ECDHE-ECDSA-AES128-GCM-SHA256"
    value = "true"
  }

  policy_attribute {
    name  = "Protocol-TLSv1.2"
    value = "true"
  }
}

resource "aws_load_balancer_policy" "negative5" {
  load_balancer_name = aws_elb.wu-tang.name
  policy_name        = "wu-tang-ssl"
  policy_type_name   = "SSLNegotiationPolicyType"

  policy_attribute {
    name  = "Reference-Security-Policy"
    value = "ELBSecurityPolicy-TLS-1-1-2017-01"
  }
}

resource "aws_load_balancer_backend_server_policy" "negative6" {
  load_balancer_name = aws_elb.wu-tang.name
  instance_port      = 443

  policy_names = [
    aws_load_balancer_policy.wu-tang-root-ca-backend-auth-policy.policy_name,
  ]
}

resource "aws_load_balancer_listener_policy" "negative7" {
  load_balancer_name = aws_elb.wu-tang.name
  load_balancer_port = 443

  policy_names = [
    aws_load_balancer_policy.wu-tang-ssl.policy_name,
  ]
}