GoTestWAF adds API attack testing via OpenAPI support

CI/CD support is next for WAF security tool

Popular open source hacking tool GoTestWAF has become the first utility of its type to evaluate API security platforms, Black Hat USA attendees have learned.

Launched in April 2020, the security testing tool simulates OWASP and API exploits to test the detection capabilities of web application firewalls (WAFs), NGWAFs, RASPs, WAAPs, and, now, API security tools.

It supports REST, GraphQL, gRPC, WebSockets, SOAP, XMLRPC, and legacy APIs.

OpenAPI-based scanning has been introduced “so you can scan exactly what is defined in your API spec during the attack simulation”, Brandon Shope, principal security engineer at Wallarm, told attendees at his Arsenal session yesterday (August 11).

The GoTestWAF GitHub repo explains how OpenAPI (formerly Swagger) file scans work, which OpenAPI features are supported, and how “instead of constructing requests that are simple in structure and send them to the URL specified at startup, GoTestWAF creates valid requests based on the application’s API description in the OpenAPI 3.0 format”.

Wallarm also demonstrated its open-source API Firewall at Black Hat USA 2022, including a new feature that blocklists compromised tokens and cookies.

More attack types incoming

Other new GoTestWAF features currently in development, meanwhile, are a daemon for CI/CD pipelines with API and server mode, and support for additional attack types, including Java, Python, and .NET serialization attacks, said Shope.

GoTestWAF generates malicious requests using encoded payloads placed in different parts of HTTP requests. The results indicate the number and percentage of path traversal, shell injection, cross-site scripting (XSS), and various other attack types blocked by the security tool.

GoTestWAF compares scan results to ModSec as a baseline, Shope said, and presents them in a “readable, nicely formatted PDF”. Wallarm CEO Ivan Novikov described this as a “really important” feature ahead of Shope’s presentation.

Testing for false negatives and positives is seen by Wallarm as invaluable given WAFs’ notoriety for generating false positives, which the API security firm says often occupies users at the expense of testing false negative rates.

Community payloads

Multiple ‘nested’ encoding support, codeless checks with YAML files, dockerization, and community payloads were also highlighted at the Las Vegas event.

Community support is a significant factor in the tool’s appeal, Novikov told The Daily Swig, citing community test cases documented by researchers from security intelligence search engine Vulners team “and then supported by others”.

GoTestWAF is already “used about 100 times a week” and asked about during sales and marketing calls by “about five enterprise companies a week”, according to Novikov.

Wallarm launched a free Online WAF tester for the tool last month.