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.

Table Of Contents


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.

Using Docker

Thanks to Github Container Registry, we are able to provide you some freshly-build Docker images!

docker run scan -v debug
docker run scan -v debug

But if you prefer, you can also build it locally, see below:

Build Locally

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

Using Docker

docker run gochopchop scan

Custom Configuration File

docker run -v ./:/app chopchop scan -c /app/chopchop.yml

What’s Next

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.

Available Flags

You can find the available flags available for the scan command :

FlagFull flagDescription
-h--helpHelp wizard
-v--verbosityVerbose level of logging
-c--signaturePath of custom signature file
-k--insecureDisable SSL Verification
-u--url-filePath to a specified file containing urls to test
-b--max-severityBlock the CI pipeline if severity is over or equal specified flag
-e--exportExport type of the output (csv and/or json)
--export-filenameSpecify the filename for the export file(s)
-t--timeoutTimeout for the HTTP requests
--severity-filterFilter Plugins by severity
--plugin-filterFilter Plugins by name of plugin
--threadsNumber of concurrent threads

Advanced Usage

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 --insecure
  • Ability to scan with a custom configuration file (including custom plugins)
$ ./gochopchop scan --insecure --signature test_config.yml
  • Ability to list all the plugins or by severity : plugins or  plugins --severity High
$ ./gochopchop plugins --severity High
  • Ability to specify number of concurrent threads : --threads 4 for 4 workers
$ ./gochopchop plugins --threads 4
  • Ability to block the CI pipeline by severity level (equal or over specified severity) : --max-severity Medium
$ ./gochopchop scan --max-severity Medium
  • Ability to specify specific signatures to be checked
./gochopchop scan --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  --export=csv,json --export-filename results

Creating A New Check

Writing a new check is as simple as :

  - endpoint: "/.git/config"
      - name: Git exposed
          - "[branch"
        remediation: Do not deploy .git folder on production servers
        description: Verifies that the GIT repository is accessible from the site
        severity: "High"

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:

AttributeTypeDescriptionOptional ?Example
namestringName of the checkNoGit exposed
descriptionstringA small description for the checkNoEnsure .git repository is not accessible from the webroot
remediationstringGive a remediation for this specific “issue”NoDo not deploy .git folder on production servers
severityEnum(“High”, “Medium”, “Low”, “Informational”)Rate the criticity if it triggers in your environmentNoHigh
status_codeintegerThe HTTP status code that should be returnedYes200
headersList of stringList of headers there should be in the HTTP responseYesN/A
no_headersList of stringList of headers there should NOT be in the HTTP responseYesN/A
matchList of stringList the strings there should be in the HTTP responseYes“[branch”
no_matchList of stringList the strings there should NOT be in the HTTP responseYesN/A
query_stringGET parameters that have to be passed to the endpointStringYesquery_string: "id=FOO-chopchoptest"