> For the complete documentation index, see [llms.txt](https://angelica.gitbook.io/hacktricks/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://angelica.gitbook.io/hacktricks/network-services-pentesting/4840-pentesting-opc-ua.md). # 4840 - OPC Unified Architecture {% hint style="success" %} Learn & practice AWS Hacking:

[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)

\ Learn & practice GCP Hacking:

[**HackTricks Training GCP Red Team Expert (GRTE)**

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{% endhint %}

**Get a hacker's perspective on your web apps, network, and cloud** **Find and report critical, exploitable vulnerabilities with real business impact.** Use our 20+ custom tools to map the attack surface, find security issues that let you escalate privileges, and use automated exploits to collect essential evidence, turning your hard work into persuasive reports. {% embed url="" %} ## Basic Information **OPC UA**, standing for **Open Platform Communications Unified Access**, is a crucial open-source protocol used in various industries like Manufacturing, Energy, Aerospace, and Defence for data exchange and equipment control. It uniquely enables different vendors' equipment to communicate, especially with PLCs. Its configuration allows for strong security measures, but often, for compatibility with older devices, these are lessened, exposing systems to risks. Additionally, finding OPC UA services can be tricky since network scanners might not detect them if they're on nonstandard ports. **Default port:** 4840 ``` PORT STATE SERVICE REASON 4840/tcp open unknown syn-ack ``` ## Pentesting OPC UA To reveal security issues in OPC UA servers, scan it with [OpalOPC](https://opalopc.com/). ```bash opalopc -vv opc.tcp://$target_ip_or_hostname:$target_port ``` ### Exploiting vulnerabilities If authentication bypass vulnerabilities are found, you can configure an [OPC UA client](https://www.prosysopc.com/products/opc-ua-browser/) accordingly and see what you can access. This may allow anything from merely reading process values to actually operating heavy-duty industrial equipment. To get a clue of the device you have access to, read the "ServerStatus" node values in the address space and google for a usage manual. ## Shodan * `port:4840` ## References *

[**HackTricks Training AWS Red Team Expert (ARTE)**](https://training.hacktricks.xyz/courses/arte)

\ Learn & practice GCP Hacking:

[**HackTricks Training GCP Red Team Expert (GRTE)**

](https://training.hacktricks.xyz/courses/grte)

Support HackTricks

{% endhint %} --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://angelica.gitbook.io/hacktricks/network-services-pentesting/4840-pentesting-opc-ua.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.