Audit Your Web Applications with AVA

Hosting a web application is an excellent way to expose useful services to the public, but it comes at a cost: vulnerabilities in your web apps could allow attackers to access important systems, endangering your customers and your business.

AVA exposes vulnerabilities like a magnifying glass finding flaws

The Indeed Security team developed Another Vulnerability Auditor (AVA) to address this problem. By using AVA to automate application scans, we can continuously monitor production and QA systems for potential vulnerabilities. And, because we have released it as an open source tool, you can use it to monitor your applications as well.

How does it work?

AVA scans a set of application endpoints, defined in HTTP Archive (HAR) format. The HAR file catalogs the URL, headers, cookies, and POST data for HTTP requests. AVA uses this information to model endpoints and scan them using a combination of auditors and checks.

Auditors

Auditors determine the HTTP elements that AVA audits. These include URLs, headers, cookies, and POST data.

Type What does it audit?
Cookie Individual cookies in the Cookie request header
Header Most request headers
JSON JSON data in the request body
Multipart Multipart form data in the request body
Parameter Parameters in the URL query string and request body
Response Aspects of a response (passive audit)
Text Plain text data in the request body
URL Request URL

Checks

Checks determine the types of security vulnerabilities AVA checks. These include cross-site scripting, open redirects, SQL injection, and shell injection.

Type What does it check for?
Code injection Code injection in Python’s pickle and eval statements
Header injection Header injection in responses
Open redirect Open redirects to arbitrary URLs
Path traversal Path traversal on the local filesystem
Shell injection Shell injection in Bash statements
SQL injection SQL injection in database queries
Cross-site scripting HTML and JavaScript injection in responses
XML external entity XML external entities in XML documents
Personally Identifiable Information (PII) Email addresses, credit cards, and Social Security numbers

How can I use it?

We designed AVA for use within automated systems. We automate AVA with Docker Swarm and Jenkins. However, you can use AVA anywhere Python can be installed.

Use in Docker Swarm

Indeed’s Security team uses Docker Swarm to automate AVA and scan public-facing applications daily. This allows us to identify vulnerabilities shortly after they are introduced. The pipeline has three components:

  • Enricher combines data from sources, such as WES, into endpoint definitions
  • Scheduler maintains a schedule and configuration
  • Vulnerability manager stores reports and displays vulnerability information

The process is as follows:

  1. The scheduler contacts the enricher and requests endpoint definitions for the current application.
  2. The enricher returns these definitions in HAR format.
  3. The scheduler pushes the HAR data and configuration settings to AVA.
  4. AVA runs the configured scan against the application and generates a report.
  5. AVA sends the report to the vulnerability manager for storage.

Diagram showing how AVA finds vulnerabilities with Docker Swarm

Use in Jenkins

We also use AVA in Jenkins to examine systems in our QA environment. This allows us to identify vulnerabilities before they reach production. The pipeline has two components: functional tests and AVA. The functional tests are a collection of Selenium-based test cases for verifying release candidates in QA.

The process is as follows:

  1. Functional tests run against the application.
  2. A proxy collects traffic from the tests and exports it as HAR files.
  3. AVA scans the application using the exported HAR files.
  4. AVA provides a report documenting the results of the scan.

Diagram showing how AVA finds vulnerabilities with Jenkins

How can I get AVA?

We’ve made AVA available and open source on Git. Download it, try it out, and reach out to us on GitHub or Twitter if you need any help. You can open an issue on the GitHub repository, or hit us up on Twitter.


Cross-posted on Medium.

Tweet about this on TwitterShare on FacebookShare on LinkedInShare on Google+Share on RedditEmail this to someone