aws-security-audit

What this skill does

# AWS Security Audit

Perform comprehensive security assessments of AWS environments to identify vulnerabilities and misconfigurations.

## When to Use
Use this skill when you need to audit AWS security posture, identify vulnerabilities, or prepare for compliance assessments.

## Audit Categories

**Identity & Access Management**
- Overly permissive IAM policies
- Unused IAM users and roles
- MFA enforcement gaps
- Root account usage
- Access key rotation

**Network Security**
- Open security groups (0.0.0.0/0)
- Public S3 buckets
- Unencrypted data in transit
- VPC flow logs disabled
- Network ACL misconfigurations

**Data Protection**
- Unencrypted EBS volumes
- Unencrypted RDS instances
- S3 bucket encryption disabled
- Backup policies missing
- KMS key rotation disabled

**Logging & Monitoring**
- CloudTrail disabled
- CloudWatch alarms missing
- VPC Flow Logs disabled
- S3 access logging disabled
- Config recording disabled

## Security Audit Commands

### IAM Security Checks

```bash
# List users without MFA
aws iam get-credential-report --output text | \
  awk -F, '$4=="false" && $1!="<root_account>" {print $1}'

# Find unused IAM users (no activity in 90 days)
aws iam list-users --query 'Users[*].[UserName]' --output text | \
while read user; do
  last_used=$(aws iam get-user --user-name "$user" \
    --query 'User.PasswordLastUsed' --output text)
  echo "$user: $last_used"
done

# List overly permissive policies (AdministratorAccess)
aws iam list-policies --scope Local \
  --query 'Policies[?PolicyName==`AdministratorAccess`]'

# Find access keys older than 90 days
aws iam list-users --query 'Users[*].UserName' --output text | \
while read user; do
  aws iam list-access-keys --user-name "$user" \
    --query 'AccessKeyMetadata[*].[AccessKeyId,CreateDate]' \
    --output text
done

# Check root account access keys
aws iam get-account-summary \
  --query 'SummaryMap.AccountAccessKeysPresent'
```

### Network Security Checks

```bash
# Find security groups open to the world
aws ec2 describe-security-groups \
  --query 'SecurityGroups[?IpPermissions[?IpRanges[?CidrIp==`0.0.0.0/0`]]].[GroupId,GroupName]' \
  --output table

# List public S3 buckets
aws s3api list-buckets --query 'Buckets[*].Name' --output text | \
while read bucket; do
  acl=$(aws s3api get-bucket-acl --bucket "$bucket" 2>/dev/null)
  if echo "$acl" | grep -q "AllUsers"; then
    echo "PUBLIC: $bucket"
  fi
done

# Check VPC Flow Logs status
aws ec2 describe-vpcs --query 'Vpcs[*].VpcId' --output text | \
while read vpc; do
  flow_logs=$(aws ec2 describe-flow-logs \
    --filter "Name=resource-id,Values=$vpc" \
    --query 'FlowLogs[*].FlowLogId' --output text)
  if [ -z "$flow_logs" ]; then
    echo "No flow logs: $vpc"
  fi
done

# Find RDS instances without encryption
aws rds describe-db-instances \
  --query 'DBInstances[?StorageEncrypted==`false`].[DBInstanceIdentifier]' \
  --output table
```

### Data Protection Checks

```bash
# Find unencrypted EBS volumes
aws ec2 describe-volumes \
  --query 'Volumes[?Encrypted==`false`].[VolumeId,Size,State]' \
  --output table

# Check S3 bucket encryption
aws s3api list-buckets --query 'Buckets[*].Name' --output text | \
while read bucket; do
  encryption=$(aws s3api get-bucket-encryption \
    --bucket "$bucket" 2>&1)
  if echo "$encryption" | grep -q "ServerSideEncryptionConfigurationNotFoundError"; then
    echo "No encryption: $bucket"
  fi
done

# Find RDS snapshots that are public
aws rds describe-db-snapshots \
  --query 'DBSnapshots[*].[DBSnapshotIdentifier]' --output text | \
while read snapshot; do
  attrs=$(aws rds describe-db-snapshot-attributes \
    --db-snapshot-identifier "$snapshot" \
    --query 'DBSnapshotAttributesResult.DBSnapshotAttributes[?AttributeName==`restore`].AttributeValues' \
    --output text)
  if echo "$attrs" | grep -q "all"; then
    echo "PUBLIC SNAPSHOT: $snapshot"
  fi
done

# Check KMS key rotation
aws kms list-keys --query 'Keys[*].KeyId' --output text | \
while read key; do
  rotation=$(aws kms get-key-rotation-status --key-id "$key" \
    --query 'KeyRotationEnabled' --output text 2>/dev/null)
  if [ "$rotation" = "False" ]; then
    echo "Rotation disabled: $key"
  fi
done
```

### Logging & Monitoring Checks

```bash
# Check CloudTrail status
aws cloudtrail describe-trails \
  --query 'trailList[*].[Name,IsMultiRegionTrail,LogFileValidationEnabled]' \
  --output table

# Verify CloudTrail is logging
aws cloudtrail get-trail-status --name my-trail \
  --query 'IsLogging'

# Check if AWS Config is enabled
aws configservice describe-configuration-recorders \
  --query 'ConfigurationRecorders[*].[name,roleARN]' \
  --output table

# List S3 buckets without access logging
aws s3api list-buckets --query 'Buckets[*].Name' --output text | \
while read bucket; do
  logging=$(aws s3api get-bucket-logging --bucket "$bucket" 2>&1)
  if ! echo "$logging" | grep -q "LoggingEnabled"; then
    echo "No access logging: $bucket"
  fi
done
```

## Automated Security Audit Script

```bash
#!/bin/bash
# comprehensive-security-audit.sh

echo "=== AWS Security Audit Report ==="
echo "Generated: $(date)"
echo ""

# IAM Checks
echo "## IAM Security"
echo "Users without MFA:"
aws iam get-credential-report --output text | \
  awk -F, '$4=="false" && $1!="<root_account>" {print "  - " $1}'

echo ""
echo "Root account access keys:"
aws iam get-account-summary \
  --query 'SummaryMap.AccountAccessKeysPresent' --output text

# Network Checks
echo ""
echo "## Network Security"
echo "Security groups open to 0.0.0.0/0:"
aws ec2 describe-security-groups \
  --query 'SecurityGroups[?IpPermissions[?IpRanges[?CidrIp==`0.0.0.0/0`]]].GroupId' \
  --output text | wc -l

# Data Protection
echo ""
echo "## Data Protection"
echo "Unencrypted EBS volumes:"
aws ec2 describe-volumes \
  --query 'Volumes[?Encrypted==`false`].VolumeId' \
  --output text | wc -l

echo ""
echo "Unencrypted RDS instances:"
aws rds describe-db-instances \
  --query 'DBInstances[?StorageEncrypted==`false`].DBInstanceIdentifier' \
  --output text | wc -l

# Logging
echo ""
echo "## Logging & Monitoring"
echo "CloudTrail status:"
aws cloudtrail describe-trails \
  --query 'trailList[*].[Name,IsLogging]' \
  --output table

echo ""
echo "=== End of Report ==="
```

## Security Score Calculator

```python
#!/usr/bin/env python3
# security-score.py

import boto3
import json

def calculate_security_score():
    iam = boto3.client('iam')
    ec2 = boto3.client('ec2')
    s3 = boto3.client('s3')
    
    score = 100
    issues = []
    
    # Check MFA
    try:
        report = iam.get_credential_report()
        users_without_mfa = 0
        # Parse report and count
        if users_without_mfa > 0:
            score -= 10
            issues.append(f"{users_without_mfa} users without MFA")
    except:
        pass
    
    # Check open security groups
    sgs = ec2.describe_security_groups()
    open_sgs = 0
    for sg in sgs['SecurityGroups']:
        for perm in sg.get('IpPermissions', []):
            for ip_range in perm.get('IpRanges', []):
                if ip_range.get('CidrIp') == '0.0.0.0/0':
                    open_sgs += 1
                    break
    
    if open_sgs > 0:
        score -= 15
        issues.append(f"{open_sgs} security groups open to internet")
    
    # Check unencrypted volumes
    volumes = ec2.describe_volumes()
    unencrypted = sum(1 for v in volumes['Volumes'] if not v['Encrypted'])
    
    if unencrypted > 0:
        score -= 20
        issues.append(f"{unencrypted} unencrypted EBS volumes")
    
    print(f"Security Score: {score}/100")
    print("\nIssues Found:")
    for issue in issues:
        print(f"  - {issue}")
    
    return score

if __name__ == "__main__":
    calculate_security_score()
```

## Compliance Mapping

**CIS AWS Foundations Benchmark**
- 1.1: Root account usage
- 1.2-1.14: IAM policies and MFA
- 2.1-2.9: Logging (CloudTrail, Config, VPC Flow Logs)
- 4.1-4.3: Monitoring and alerting

**PCI-DSS**
- Re