KubeStalk : Discovers Kubernetes Attack Surface From A Black-Box Perspective

KubeStalk is a tool to discover Kubernetes and related infrastructure based attack surface from a black-box perspective. This tool is a community version of the tool used to probe for unsecured Kubernetes clusters around the internet during Project Resonance – Wave 9.

Usage

The GIF below demonstrates usage of the tool:

Installation

KubeStalk is written in Python and requires the requests library.

To install the tool, you can clone the repository to any directory:

git clone https://github.com/redhuntlabs/kubestalk

Once cloned, you need to install the requests library using python3 -m pip install requests or:

python3 -m pip install -r requirements.txt

Everything is setup and you can use the tool directly.

Command-line Arguments

A list of command line arguments supported by the tool can be displayed using the -h flag.

$ python3 kubestalk.py  -h

    +---------------------+
    |  K U B E S T A L K  |
    +---------------------+   v0.1

[!] KubeStalk by RedHunt Labs - A Modern Attack Surface (ASM) Management Company
[!] Author: 0xInfection (RHL Research Team)
[!] Continuously Track Your Attack Surface using https://redhuntlabs.com/nvadr.

usage: ./kubestalk.py <url(s)>/<cidr>

Required Arguments:
  urls                  List of hosts to scan

Optional Arguments:
  -o OUTPUT, --output OUTPUT
                        Output path to write the CSV file to
  -f SIG_FILE, --sig-dir SIG_FILE
                        Signature directory path to load
  -t TIMEOUT, --timeout TIMEOUT
                        HTTP timeout value in seconds
  -ua USER_AGENT, --user-agent USER_AGENT
                        User agent header to set in HTTP requests
  --concurrency CONCURRENCY
                        No. of hosts to process simultaneously
  --verify-ssl          Verify SSL certificates
  --version             Display the version of KubeStalk and exit.

Basic Usage

To use the tool, you can pass one or more hosts to the script. All targets passed to the tool must be RFC 3986 complaint, i.e. must contain a scheme and hostname (and port if required).

A basic usage is as below:

$ python3 kubestalk.py https://███.██.██.███:10250

    +---------------------+
    |  K U B E S T A L K  |
    +---------------------+   v0.1

[!] KubeStalk by RedHunt Labs - A Modern Attack Surface (ASM) Management Company
[!] Author: 0xInfection (RHL Research Team)
[!] Continuously Track Your Attack Surface using https://redhuntlabs.com/nvadr.

[+] Loaded 10 signatures to scan.
[*] Processing host: https://███.██.██.██:10250
[!] Found potential issue on https://███.██.██.██:10250: Kubernetes Pod List Exposure
[*] Writing results to output file.
[+] Done.

HTTP Tuning

HTTP requests can be fine-tuned using the -t (to mention HTTP timeouts), -ua (to specify custom user agents) and the --verify-ssl (to validate SSL certificates while making requests).

Concurrency

You can control the number of hosts to scan simultanously using the --concurrency flag. The default value is set to 5.

Output

The output is written to a CSV filea and can be controlled by the --output flag.

A sample of the CSV output rendered in markdown is as belows:

host	path	issue	type	severity
https://█.█.█.█:10250	/pods	Kubernetes Pod List Exposure	core-component	vulnerability/misconfiguration
https://█.█.█.█:443	/api/v1/pods	Kubernetes Pod List Exposure	core-component	vulnerability/misconfiguration
http://█.█.██.█:80	/	etcd Viewer Dashboard Exposure	add-on	vulnerability/exposure
http://██.██.█.█:80	/	cAdvisor Metrics Web UI Dashboard Exposure	add-on	vulnerability/exposure

Version & License

The tool is licensed under the BSD 3 Clause License and is currently at v0.1.

To know more about our Attack Surface Management platform, check out NVADR.

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