# CVE-2025-40771: Missing authorization in SIMATIC CP 1542SP-1

> Unauthenticated remote attackers can access configuration data on affected Siemens SIMATIC communication processors due to missing authentication.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Oct 2025
- **Updated:** 14 Oct 2025
- **Also known as:** GHSA-8x4j-8hhc-j8jf

## What is CVE-2025-40771?

CVE-2025-40771 is a critical missing authorization vulnerability in Siemens SIMATIC CP 1542SP-1, published on 14 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability has been identified in SIMATIC CP 1542SP-1 (6GK7542-6UX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1542SP-1 IRC (6GK7542-6VX00-0XE0) (All versions < V2.4.24), SIMATIC CP 1543SP-1 (6GK7543-6WX00-0XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1542SP-1 IRC TX RAIL (6AG2542-6VX00-4XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC (6AG1543-6WX00-7XE0) (All versions < V2.4.24), SIPLUS ET 200SP CP 1543SP-1 ISEC TX RAIL (6AG2543-6WX00-4XE0) (All versions < V2.4.24). Affected devices do not properly authenticate configuration connections. This could allow an unauthenticated remote attacker to access the configuration data.

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

## Which versions are affected by CVE-2025-40771?


## How do I fix CVE-2025-40771?

No fix has been published for CVE-2025-40771 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-40771 being exploited?

There is no known exploitation of CVE-2025-40771 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40771 and fix it if it is affected.

What it is: CVE-2025-40771 is a critical missing authorization vulnerability in Siemens SIMATIC CP 1542SP-1, published on 14 Oct 2025. 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-2025-40771 in the wild and no public exploit code.

Affected product: Siemens SIMATIC CP 1542SP-1. 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-2025-40771/ (Markdown: https://insights.sbomify.com/CVE-2025-40771/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40771
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40771
- OSV: https://osv.dev/vulnerability/CVE-2025-40771

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40771/
Summaries are generated and may contain mistakes; the official description above is the record.