---
title: Unrestricted security group ingress
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Infrastructure as Code (IaC)
  Security > IaC Security Rules > Unrestricted security group ingress
---

> For the complete documentation index, see [llms.txt](https://docs.datadoghq.com/llms.txt).

# Unrestricted security group ingress

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com, us2.ddog-gov.com

{% alert level="danger" %}
This product is not supported for your selected [Datadog site](https://docs.datadoghq.com/getting_started/site.md). ({% placeholder "user-datadog-site-name" /%}).
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{% /callout %}

## Metadata{% #metadata %}

**Id:** `cloudformation-aws-unrestricted-security-group-ingress` 

**Provider:** AWS

**Platform:** CloudFormation

**Severity:** High

**Category:** Networking and Firewall

#### Learn More{% #learn-more %}

- [Provider Reference](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-ec2-security-group-ingress.html)

### Description{% #description %}

Security groups must not allow ingress from the entire internet (`0.0.0.0/0` or `::/0`) because such wide-open rules expose instances and services to unauthorized access, brute-force attempts, and remote exploitation.

This rule checks `AWS::EC2::SecurityGroupIngress` resources (`Properties.CidrIp` / `Properties.CidrIpv6`) and `AWS::EC2::SecurityGroup` resources' `Properties.SecurityGroupIngress` entries. `CidrIp` must not be `0.0.0.0/0` and `CidrIpv6` must not be `::/0`. Resources with those values will be flagged.

To remediate, restrict access to specific trusted CIDR ranges, use VPC-only ranges, prefix lists, or reference other security groups via `SourceSecurityGroupId`/`SourceSecurityGroupOwnerId`.

Secure examples (CloudFormation YAML):

```yaml
MyRestrictedIngress:
  Type: AWS::EC2::SecurityGroupIngress
  Properties:
    GroupId: !Ref MySecurityGroup
    IpProtocol: tcp
    FromPort: 22
    ToPort: 22
    CidrIp: 10.0.0.0/16
```

```yaml
MySGToSGIngress:
  Type: AWS::EC2::SecurityGroupIngress
  Properties:
    GroupId: !Ref MySecurityGroup
    IpProtocol: tcp
    FromPort: 443
    ToPort: 443
    SourceSecurityGroupId: sg-0123456789abcdef0
```

## Compliant Code Examples{% #compliant-code-examples %}

```yaml
Resources:
  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow http to client host
      VpcId:
         Ref: myVPC
      SecurityGroupIngress:
      - IpProtocol: tcp
        Description: TCP
        FromPort: 80
        ToPort: 80
        CidrIp: 192.0.2.0/24
      SecurityGroupEgress:
      - IpProtocol: tcp
        Description: TCP
        FromPort: 80
        ToPort: 80
        CidrIp: 192.0.2.0/24
  OutboundRule:
    Type: AWS::EC2::SecurityGroupEgress
    Properties:
      Description: TCP
      IpProtocol: tcp
      FromPort: 0
      ToPort: 0
      CidrIp: 192.0.2.0/24
      DestinationSecurityGroupId:
        Fn::GetAtt:
        - TargetSG
        - GroupId
      GroupId:
        Fn::GetAtt:
        - SourceSG
        - GroupId
  InboundRule:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      Description: TCP
      IpProtocol: tcp
      FromPort: 0
      ToPort: 0
      CidrIpv6: 2001:0DB8:1234::/48
      SourceSecurityGroupId:
        Fn::GetAtt:
        - SourceSG
        - GroupId
      GroupId:
        Fn::GetAtt:
        - TargetSG
        - GroupId
```

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```yaml
Resources:
  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow http to client host
      VpcId:
         Ref: myVPC
      SecurityGroupIngress:
      - IpProtocol: tcp
        Description: TCP
        FromPort: 80
        ToPort: 80
        CidrIp: 0.0.0.0/0
      SecurityGroupEgress:
      - IpProtocol: tcp
        Description: TCP
        FromPort: 80
        ToPort: 80
        CidrIp: 0.0.0.0/0
  OutboundRule:
    Type: AWS::EC2::SecurityGroupEgress
    Properties:
      Description: TCP
      IpProtocol: tcp
      FromPort: 0
      ToPort: 65535
      CidrIp: 0.0.0.0/0
      DestinationSecurityGroupId:
        Fn::GetAtt:
        - TargetSG
        - GroupId
      GroupId:
        Fn::GetAtt:
        - SourceSG
        - GroupId
  InboundRule:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      Description: TCP
      IpProtocol: tcp
      FromPort: 0
      ToPort: 65535
      CidrIpv6: ::/0
      SourceSecurityGroupId:
        Fn::GetAtt:
        - SourceSG
        - GroupId
      GroupId:
        Fn::GetAtt:
        - TargetSG
        - GroupId
```