prowler/checks/check_extra777

#!/usr/bin/env bash

# Prowler - the handy cloud security tool (copyright 2020) 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.

# Current VPC Limit is 120 rules (60 inbound and 60 outbound)
# Reference: https://docs.aws.amazon.com/vpc/latest/userguide/amazon-vpc-limits.html

CHECK_ID_extra777="7.77"
CHECK_TITLE_extra777="[extra777] Find VPC security groups with many ingress or egress rules (Not Scored) (Not part of CIS benchmark)"
CHECK_SCORED_extra777="NOT_SCORED"
CHECK_TYPE_extra777="EXTRA"
CHECK_SEVERITY_extra777="Medium"
CHECK_ASFF_RESOURCE_TYPE_extra777="AwsEc2SecurityGroup"
CHECK_ALTERNATE_check777="extra777"
CHECK_SERVICENAME_extra777="ec2"
CHECK_RISK_extra777='If Security groups are not properly configured the attack surface is increased. '
CHECK_REMEDIATION_extra777='Use a Zero Trust approach. Narrow ingress traffic as much as possible. Consider north-south as well as east-west traffic.'
CHECK_DOC_extra777='https://docs.aws.amazon.com/vpc/latest/userguide/VPC_SecurityGroups.html'
CHECK_CAF_EPIC_extra777='Infrastructure Security'

extra777(){
    THRESHOLD=50
    textInfo "Looking for VPC security groups with more than ${THRESHOLD} rules across all regions...  "

    for regx in ${REGIONS}; do
        SECURITY_GROUP_IDS=$(${AWSCLI} ec2 describe-security-groups \
                             ${PROFILE_OPT} \
                             --region ${regx} \
                             --query 'SecurityGroups[*].GroupId' \
                             --output text | xargs
                             )

        for SECURITY_GROUP in ${SECURITY_GROUP_IDS}; do

            INGRESS_TOTAL=$(${AWSCLI} ec2 describe-security-groups \
                            ${PROFILE_OPT} \
                            --filter "Name=group-id,Values=${SECURITY_GROUP}" \
                            --query "SecurityGroups[*].IpPermissions[*].IpRanges" \
                            --region ${regx} \
                            --output text | wc -l | xargs
                            )

            EGRESS_TOTAL=$(${AWSCLI} ec2 describe-security-groups \
                            ${PROFILE_OPT} \
                            --filter "Name=group-id,Values=${SECURITY_GROUP}" \
                            --query "SecurityGroups[*].IpPermissionsEgress[*].IpRanges" \
                            --region ${regx} \
                            --output text | wc -l | xargs
                            )

            if [[ (${INGRESS_TOTAL} -ge ${THRESHOLD}) || (${EGRESS_TOTAL} -ge ${THRESHOLD}) ]]; then
                textFail "${regx}: ${SECURITY_GROUP} has ${INGRESS_TOTAL} inbound rules and ${EGRESS_TOTAL} outbound rules" "${regx}" "${SECURITY_GROUP}"
            fi
        done
    done
}