#!/usr/bin/env bash

# Prowler - the handy cloud security tool (copyright 2019) by Toni de la Fuente
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may not
# use this file except in compliance with the License. You may obtain a copy
# of the License at http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed
# under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
# CONDITIONS OF ANY KIND, either express or implied. See the License for the
# specific language governing permissions and limitations under the License.

CHECK_ID_check45="4.5"
CHECK_TITLE_check45="[check45] Ensure no Network ACLs allow ingress from 0.0.0.0/0 to SSH port 22"
CHECK_SCORED_check45="SCORED"
CHECK_TYPE_check45="LEVEL2"
CHECK_SEVERITY_check45="High"
CHECK_ASFF_TYPE_check45="Software and Configuration Checks/Industry and Regulatory Standards/CIS AWS Foundations Benchmark"
CHECK_ASFF_RESOURCE_TYPE_check45="AwsEc2NetworkAcl"
CHECK_ALTERNATE_check401="check45"
CHECK_SERVICENAME_check45="ec2"
CHECK_RISK_check45='Even having a perimeter firewall; having network acls open allows any user or malware with vpc access to scan for well known and sensitive ports and gain access to instance.'
CHECK_REMEDIATION_check45='Apply Zero Trust approach. Implement a process to scan and remediate unrestricted or overly permissive network acls. Recommended best practices is to narrow the definition for the minimum ports required.'
CHECK_DOC_check45='https://docs.aws.amazon.com/vpc/latest/userguide/vpc-network-acls.html'
CHECK_CAF_EPIC_check45='Infrastructure Security'

check45(){
  for regx in $REGIONS; do
    NACL_LIST=$($AWSCLI ec2 describe-network-acls --query 'NetworkAcls[?Entries[?(((!PortRange) || (PortRange.From<=`22` && PortRange.To>=`22`)) && ((CidrBlock == `0.0.0.0/0`) && (Egress == `false`) && (RuleAction == `allow`)))]].{NetworkAclId:NetworkAclId}' $PROFILE_OPT --region $regx --output text)
    if [[ $NACL_LIST ]];then
      for NACL in $NACL_LIST;do
        textInfo "$regx: Found Network ACL: $NACL open to 0.0.0.0/0 for SSH port 22" "$regx" "$NACL"
      done
    else
      textPass "$regx: No Network ACL found with SSH port 22 open to 0.0.0.0/0" "$regx" "$NACL"
    fi
  done
}