# CVE-2023-27396: Missing authorization in Multiple OMRON products which implement FINS protocol

> Attackers can execute arbitrary commands or retrieve system information from OMRON PLCs due to lack of authentication in the FINS protocol.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Jun 2023
- **Updated:** 24 Dec 2024
- **Also known as:** GHSA-5mw2-67q5-9c2w

## What is CVE-2023-27396?

CVE-2023-27396 is a critical missing authorization vulnerability in Multiple OMRON products which implement FINS protocol, published on 19 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

FINS (Factory Interface Network Service) is a message communication protocol, which is designed to be used in closed FA (Factory Automation) networks, and is used in FA networks composed of OMRON products. Multiple OMRON products that implement FINS protocol contain following security issues -- (1)Plaintext communication, and (2)No authentication required. When FINS messages are intercepted, the contents may be retrieved. When arbitrary FINS messages are injected, any commands may be executed on, or the system information may be retrieved from, the affected device. Affected products and versions are as follows: SYSMAC CS-series CPU Units, all versions, SYSMAC CJ-series CPU Units, all versions, SYSMAC CP-series CPU Units, all versions, SYSMAC NJ-series CPU Units, all versions, SYSMAC NX1P-series CPU Units, all versions, SYSMAC NX102-series CPU Units, all versions, and SYSMAC NX7 Database Connection CPU Units (Ver.1.16 or later)

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2023-27396?

It affects 271 products.


Products: Omron Cj2h-Cpu64-Eip Firmware, Omron Cj2h-Cpu64 Firmware, Omron Cj2h-Cpu65-Eip Firmware, Omron Cj2h-Cpu65 Firmware, Omron Cj2h-Cpu66-Eip Firmware, Omron Cj2h-Cpu66 Firmware, Omron Cj2h-Cpu67-Eip Firmware, Omron Cj2h-Cpu67 Firmware, Omron Cj2h-Cpu68-Eip Firmware, Omron Cj2h-Cpu68 Firmware, Omron Cj2m-Cpu11 Firmware, Omron Cj2m-Cpu12 Firmware, Omron Cj2m-Cpu13 Firmware, Omron Cj2m-Cpu14 Firmware, Omron Cj2m-Cpu15 Firmware, Omron Cj2m-Cpu31 Firmware, Omron Cj2m-Cpu32 Firmware, Omron Cj2m-Cpu33 Firmware, Omron Cj2m-Cpu34 Firmware, Omron Cj2m-Cpu35 Firmware and 251 more.

## How do I fix CVE-2023-27396?

No fix has been published for CVE-2023-27396 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-27396 being exploited?

There is no known exploitation of CVE-2023-27396 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-27396 and fix it if it is affected.

What it is: CVE-2023-27396 is a critical missing authorization vulnerability in Multiple OMRON products which implement FINS protocol, published on 19 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-27396 in the wild and no public exploit code.

Affected product: Multiple OMRON products which implement FINS protocol. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-27396/ (Markdown: https://insights.sbomify.com/CVE-2023-27396/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-27396
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-27396
- OSV: https://osv.dev/vulnerability/CVE-2023-27396

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-27396/
Summaries are generated and may contain mistakes; the official description above is the record.