Monday, 3 April 2017

Exploring APIs with ZAP

APIs can be challenging for security testing for a variety of reasons.
The first problem you will encounter is how to effectively explore an API - most APIs cannot be explored using browsing or standard spidering techniques.
However many APIs are described using technologies such as:

These standards define the API endpoints and can be imported into ZAP using 2 optional add-ons.

Installing the add-ons

In order to import the API definitions you will need to add the relevant add-ons from the ZAP Marketplace.

To do this via the UI:

  1. Click on the ‘Manage Add-ons’ button
  2. Select the ‘Marketplace’ tab
  3. Click on the ‘Check for Updates’ button if no add-ons are shown
  4. Select and install the add-ons:
    • OpenAPI Support
    • SOAP Scanner

To install them via the command line is even easier - just start ZAP with the command line flags: “-addoninstall soap -addoninstall openapi”
./ -addoninstall soap -addoninstall openapi

Importing via the UI

These add-ons add the following items under the ‘Tools’ menu:
  • Import a WSDL file from local file system
  • Import a WSDL file from a URL
  • Import an OpenAPI definition from the local file system
  • Import an OpenAPI definition from a URL

These menu items will open new dialogs which will allow you to specify the relevant file or URL to import.

When the definitions have been imported they will be shown in the Sites tree:

Importing via the API

Both add-ons support importing API definitions from URLs and local files.
You can try these out via the API Web UI:

Using the Java API client this can be done with calls like:

Map<String, String> map1 = new HashMap<>();
map1.put("file", "/home/user/openapi.json");
ApiResponse resp =
  api.callApi("openapi", "action", "importFile", map1);

Map<String, String> map2 = new HashMap<>();
map2.put("url", "https://localhost/openapi.json");
ApiResponse resp =
  api.callApi("openapi", "action", "importUrl", map2);

Map<String, String> map3 = new HashMap<>();
map3.put("file", "/home/user/soap.xml");
ApiResponse resp =
  api.callApi("soap", "action", "importFile", map3);

Map<String, String> map4 = new HashMap<>();
map4.put("url", "https://localhost/soap.xml");
ApiResponse resp =
  api.callApi("soap", "action", "importUrl", map4);

Using the Python API client this can be done with calls like:

print zap._request(
  zap.base + 'openapi/action/importFile/',

print zap._request(
  zap.base + 'openapi/action/importUrl/',

print zap._request(
  zap.base + 'soap/action/importFile/',

print zap._request(
  zap.base + 'soap/action/importUrl/',


Both of the add-ons automatically detect the relevant API definition file while spidering and will explore the definitions as long as they are in scope.
This means that you can explore an API by spidering from the URL of the definition as long as it is on the same domain as the API.

Next steps

Once you have added your API to the Sites tree using any of the above options you can then use any of the other ZAP components on the API, including the active scanner and fuzzer.

Note that the SOAP Scanner add-on also adds 2 additional scan rules that specifically target SOAP and XML URLs:

Monday, 6 February 2017

Introducing the JxBrowser add-on for ZAP

As modern web applications are increasing their reliance on JavaScript, security tools that do not understand JavaScript will not be able to work effectively with them.  ZAP already has components like the Ajax Spider and DOM XSS scanner that work by launching browsers and controlling them via Selenium, and we are planning to make much more use of browsers in the future.

To that end we are planning on releasing a new ZAP add-on which will contain JxBrowser, a wrapper around Chromium. We want ZAP to work as effectively as possible out of the box, and to be as easy to automate as possible. Being able to package JxBrowser in an add-on gives us an up to date browser that we know will work without any other user actions. While the add-on does contain a bundled version of Chromium it will not install Chrome on your computer. Your existing browsers and browser preferences will not be affected.

Please note: While JxBrowser is a commercial closed source wrapper around Chromium, TeamDev has generously given us a permanent free license to allow us to redistribute JxBrowser with ZAP. Most importantly ZAP will stay completely free. Additionally we will not be including the JxBrowser with the ZAP ‘core’ release which we maintain. It will also be very easy to remove the JxBrowser add-on from ZAP via the command line, in the same way that any other add-ons can be removed:
./ -addonuninstall jxbrowser

Why are we doing this?
As this is the first time we will have done anything like this I wanted to explain why we are packaging a closed source product with ZAP, what the implications are and how you can contact us to discuss any concerns you may have.

Unfortunately it is difficult for us to know which browsers will work on any specific system. Both Firefox and Chrome could be present, but we can’t tell until we try to launch them. IE and/or Edge are only going to be available on Windows systems and although Safari is always likely to be available on Mac OS it will not work with Selenium until an extra plugin is installed. As part of this on going effort we have recently decided to package the WebDrivers for Firefox, Chrome and IE in ZAP add-ons so that you will not have to download them manually. We want to be able to default to JxBrowser while allowing you to choose to use any of the browsers as you see fit. We will also be able to do things like launch JxBrowser from within ZAP pre-configured to proxy via ZAP.

Are there any licensing restrictions for JxBrowser?
As a ZAP user you will be able to use the ZAP JxBrowser add-on for any purposes.
However if you change the ZAP source code and call the JxBrowser API from one of your own products then you will need to arrange a suitable licence with TeamDev.
It is also worth noting that while JxBrowser does not ‘phone home’ the internal Chromium functionality may call 3rd party services (spell checking, geolocation, etc) in a similar way to other browsers.

When will the add-on be available?
It's available now :) You can install it from within ZAP using the 'Manage Add-Ons' button on the ZAP toolbar. Make sure that you update any add-ons that are flagged as needing updates, in particular the Selenium and Ajax Spider ones.

If you do have any concerns about our bundling of JxBrowser then please join in the discussion on the ZAP User Group or contact me directly.