ChopChop is a command-line tool for dynamic application security testing on web applications, initially written by the Michelin CERT.
Its goal is to scan several endpoints and identify exposition of services/files/folders through the webroot. Checks/Signatures are declared in a config file (by default:
chopchop.yml), fully configurable, and especially by developers.
“Chop chop” is a phrase rooted in Cantonese. “Chop chop” means “hurry” and suggests that something should be done now and without delay.
We tried to make the build process painless and hopefully, it should be as easy as:
$ go mod download
$ go build .
There should be a resulting
gochopchop binary in the folder.
Thanks to Github Container Registry, we are able to provide you some freshly-build Docker images!
docker run ghcr.io/michelin/gochopchop scan https://foobar.com -v debug
But if you prefer, you can also build it locally, see below:
docker build -t gochopchop .
We are continuously trying to make
goChopChop as easy as possible. Scanning a host with this utility is as simple as :
$ ./gochopchop scan https://foobar.com
docker run gochopchop scan https://foobar.com
Custom configuration file
docker run -v ./:/app chopchop scan -c /app/chopchop.yml https://foobar.com
The Golang rewrite took place a couple of months ago but there’s so much to do, still. Here are some features we are planning to integrate : [x] Threading for better performance [x] Ability to specify the number of concurrent threads [x] Colors and better formatting [x] Ability to filter checks/signatures to search for [x] Mock and unit tests [x] Github CI And much more!
To quickly end-to-end test chopchop, we provided a web-server in
tests/server.go. To try it, please run
go run tests/server.go then run chopchop with the following command
./gochopchop scan http://localhost:8000 --verbosity Debug. ChopChop should print “no vulnerabilities found”.
There are also unit test that you can launch with
go test -v ./.... These tests are integrated in the github CI workflow.
You can find the available flags available for the
scan command :
||Verbose level of logging|
||Path of custom signature file|
||Disable SSL Verification|
||Path to a specified file containing urls to test|
||Block the CI pipeline if severity is over or equal specified flag|
||Export type of the output (csv and/or json)|
||Specify the filename for the export file(s)|
||Timeout for the HTTP requests|
||Filter Plugins by severity|
||Filter Plugins by name of plugin|
||Number of concurrent threads|
Here is a list of advanced usage that you might be interested in. Note: Redirectors like
> for post processing can be used.
- Ability to scan and disable SSL verification
$ ./gochopchop scan https://foobar.com --insecure
- Ability to scan with a custom configuration file (including custom plugins)
$ ./gochopchop scan https://foobar.com --insecure --signature test_config.yml
- Ability to list all the plugins or by severity :
plugins --severity High
$ ./gochopchop plugins --severity High
- Ability to specify number of concurrent threads :
--threads 4for 4 workers
$ ./gochopchop plugins --threads 4
- Ability to block the CI pipeline by severity level (equal or over specified severity) :
$ ./gochopchop scan https://foobar.com --max-severity Medium
- Ability to specify specific signatures to be checked
./gochopchop scan https://foobar.com --timeout 1 --verbosity --export=csv,json --export-filename boo --plugin-filters=Git,Zimbra,Jenkins
- Ability to list all the plugins
$ ./gochopchop plugins
- List High severity plugins
$ ./gochopchop plugins --severity High
- Set a list or URLs located in a file
$ ./gochopchop scan --url-file url_file.txt
- Export GoChopChop results in CSV and JSON format
$ ./gochopchop scan https://foobar.com --export=csv,json --export-filename results
Creating a new check
Writing a new check is as simple as :
- endpoint: "/.git/config"
- name: Git exposed
remediation: Do not deploy .git folder on production servers
description: Verifies that the GIT repository is accessible from the site
An endpoint (eg.
/.git/config) is mapped to multiple checks which avoids sending X requests for X checks. Multiple checks can be done through a single HTTP request. Each check needs those fields:
|name||string||Name of the check||No||Git exposed|
|description||string||A small description for the check||No||Ensure .git repository is not accessible from the webroot|
|remediation||string||Give a remediation for this specific “issue”||No||Do not deploy .git folder on production servers|
|severity||Enum(“High”, “Medium”, “Low”, “Informational”)||Rate the criticity if it triggers in your environment||No||High|
|status_code||integer||The HTTP status code that should be returned||Yes||200|
|headers||List of string||List of headers there should be in the HTTP response||Yes||N/A|
|no_headers||List of string||List of headers there should NOT be in the HTTP response||Yes||N/A|
|match||List of string||List the strings there should be in the HTTP response||Yes||“[branch”|
|no_match||List of string||List the strings there should NOT be in the HTTP response||Yes||N/A|
|query_string||GET parameters that have to be passed to the endpoint||String||Yes||
|Cobra||https://github.com/spf13/cobra||Apache License 2.0|
|strfmt||https://github.com/go-openapi/strfmt||Apache License 2.0|
|pkg-errors||https://github.com/pkg/errors||BSD 2 (Simplified License)|
Please, refer to the
third-party.txt file for further information.
- PyCon FR 2019 (The tool was initially developed in Python) – https://docs.google.com/presentation/d/1uVXGUpt7tC7zQ1HWegoBbEg2LHamABIqfDfiD9MWsD8/edit
- DEFCON AppSec Village 2020 “Turning offsec mindset to developer’s toolset” – https://drive.google.com/file/d/15P8eSarIohwCVW-tR3FN78KJPGbpAtR1/view
ChopChop has been released under Apache License 2.0. Please, refer to the
LICENSE file for further information.
- Paul A.
- David R. (For the Python version)
- Stanislas M. (For the Golang version)