Tool Development

Introducing citrixInspector: My Journey in Tackling CVE-2023-3519 in Citrix Gateways

Bryan Smith
Jul 20, 2023
min read
citrixInspector python tool to Accurately fingerprint and detect vulnerable (and patched!) versions of Netscaler / Citrix ADC to CVE-2023-3519

Introducing citrixInspector: My Journey in Tackling CVE-2023-3519 in Citrix Gateways

In the vast digital landscape, threats evolve faster than ever before. Recognizing the imminent need for specialized tools to combat these challenges, I created citrixInspector, which I'm thrilled to share with you.

So, What Exactly is citrixInspector?

I designed citrixInspector as a Python-based vulnerability scanner specifically to detect the CVE-2023-3519 vulnerability in Citrix Gateways. Its distinct feature is its emphasis on passive analysis and fingerprinting. This allows for an efficient, non-invasive assessment of target websites based on an exhaustive series of checks.

Why I Created citrixInspector

I have always been passionate about cybersecurity, and witnessing the broader community utilizing open-source tools like mine brings immense joy. With the frequent emergence of 0days and limited initial information, tools like citrixInspector become invaluable. I believe you shouldn't solely rely on commercial tools, as sometimes they might miss out on detections. My aim was to provide an alternative, community-driven solution to ensure comprehensive security.

Recognition and the Bigger Picture

My dedication to citrixInspector and its contribution to mitigating risks associated with the Citrix vulnerability has been a rewarding journey. I took the initiative to offer a proactive solution rather than wait for commercial tools. This endeavor has not just fortified many digital landscapes but has also enriched my personal expertise in cybersecurity.

And guess what? My efforts has garnered attention in the cybersecurity space, and I'm proud to see it being leveraged by various platforms. Here are a few places (at the time of writing) where it's being used and/or mentioned!

My Recent Additions and Tweaks

  1. I integrated the ability to parse the /vpn/pluginlist.xml file, amplifying the accuracy of vulnerability checks.
  2. I added an option for users to search for common web shell IOCs (Indicators of Compromise) on their target server.
  3. I implemented an enhanced logic, with a little help from @UK_Daniel_Card & @DTCERT, to reliably determine if a target is patched.

How to Harness citrixInspector

Post a simple installation, the script is ready to analyze either a single URL or a batch from a file. I've also incorporated an option to check for IOCs and direct outputs to a log file for those who crave detailed reports. For a step-by-step guide, you can head here.

For regular updates, deeper insights, and to connect with me personally, do follow me on Twitter.

Inside the Mechanics of the Checks

citrixInspector isn't just any tool; it's a meticulous scanner:

  • It ensures the latest version of pluginslist.xml is in place.
  • It can optionally probe for known web shells.
  • It verifies that the HTTP title is "Citrix Gateway".
  • It seeks out an HTML comment tagged "frame-busting".
  • It identifies distinct Citrix Gateway icons and vhashes.

After these checks, the tool deduces the vulnerability status of the target.

Wrapping Up

In our collective quest against cyber threats, every tool counts. And with the continuous support and feedback from the community, I'm hopeful that citrixInspector will continue to evolve, offering even stronger defenses against vulnerabilities.

To everyone reading, I invite you to dive deep into citrixInspector and join me on this journey towards a safer digital world.

Here's to safer cyber horizons and happy hunting!

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