aws-security-audit

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

# 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

# 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

# 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

# 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

#!/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

#!/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

• Req