Ever find yourself looking for that showstopper exploit in a Web-app, and forgetting to check out all the low-hanging fruit? That’s intitially why we created Watcher. For one thing, we don’t want to manually inspect a Web-app for many of these issues (cookie settings, SSL configuration, information leaks, etc), but we still want to find and fix them. Watcher provides this level of security analysis, plus provides hot-spot detection to help pen-testers focus in on the spots that will lead to that showstopper exploit.

Watcher is a runtime passive-analysis tool for HTTP-based Web applications. Being passive means it won’t damage production systems, it’s completely safe to use in Cloud computing, shared hosting, and dedicated hosting environments. Watcher detects Web-application security issues as well as operational configuration issues. Watcher provides pen-testers hot-spot detection for vulnerabilities, developers quick sanity checks, and auditors PCI compliance auditing. It looks for issues related to mashups, user-controlled payloads (potential XSS), cookies, comments, HTTP headers, SSL, Flash, Silverlight, referrer leaks, information disclosure, Unicode, and more.

Watcher is a Fiddler addon which aims to assist penetration testers in passively finding Web-application vulnerabilities. The security field today has several good choices for HTTP proxies which assist auditors and pen-testers. We chose to implement this as a plugin for Fiddler which already provides the proxy framework for HTTP debugging.

Major Features:

• Passive detection of security, privacy, and PCI compliance issues in
  HTTP, HTML, Javascript, CSS, and development frameworks (e.g. ASP.NET,
  JavaServer)
• Works seamlessly with complex Web 2.0 applications while you drive the Web browser
• Non-intrusive, will not raise alarms or damage production sites
• Real-time analysis and reporting – findings are reported as they’re
  found, exportable to XML, HTML, and Team Foundation Server (TFS)
• Configurable domains with wildcard support
• Extensible framework for adding new checks

Some reasons to use Watcher include:

• Safe for the Cloud and hosting environments. Being passive gives Watcher several advantages – when applications live in the Cloud there’s often a risk that running security testing could damage the shared infrastructure. However, using a passive tool like Watcher ensures that there’s no chance of damaging Cloud-like infrastructure.

• Safe for production environments. Watcher does not attack web-applications with loads of intrusive requests, it doesn’t modify inputs to your application. Unlike crawlers and web-application scanners, Watcher does not generate dangerous traffic. It quietly analyzes normal user-interaction and makes educated reports on the security of an application.

• Low overhead, no training. If you’re building web-applications you already have a development and test staff. Fiddler has been valuable to dev and test for years as a general-purpose HTTP debugging proxy. Watcher fits seamlessly into the picture, providing valuable security insight with no special training requirements, dedicated machines, or other resources. 

Download and read more at the project website.