# Path traversal in Siemens SIMATIC PCS 7 V8.2 and others

CVE record · `CVE-2021-40358`

- **Identifiers:** `CVE-2021-40358`
- **State:** Confirmed
- **Severity:** CVSS 9.9 Critical
- **Critical:** Yes: CVSS 9+
- **CNA:** siemens
- **Weakness (CWE):** [CWE-22](https://cwe.mitre.org/data/definitions/22.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md)
- **Technologies:** [Siemens SIMATIC PCS 7 V8.2](https://agentprime.io/advisories/technology/siemens-simatic-pcs-7-v8-2.md) · [Siemens SIMATIC PCS 7 V9.0](https://agentprime.io/advisories/technology/siemens-simatic-pcs-7-v9-0.md) · [Siemens SIMATIC PCS 7 V9.1](https://agentprime.io/advisories/technology/siemens-simatic-pcs-7-v9-1.md) · [Siemens SIMATIC WinCC V15 and earlier](https://agentprime.io/advisories/technology/siemens-simatic-wincc-v15-and-earlier.md) · [Siemens SIMATIC WinCC V16](https://agentprime.io/advisories/technology/siemens-simatic-wincc-v16.md) · [Siemens SIMATIC WinCC V17](https://agentprime.io/advisories/technology/siemens-simatic-wincc-v17.md) · [Siemens SIMATIC WinCC V7.4](https://agentprime.io/advisories/technology/siemens-simatic-wincc-v7-4.md) · [Siemens SIMATIC WinCC V7.5](https://agentprime.io/advisories/technology/siemens-simatic-wincc-v7-5.md)
- **Published:** 9 Nov 2021
- **Updated:** 4 Aug 2024
- **Reviewed by a person:** No

Published by the CVE Program (CNA: siemens) at 9 Nov 2021, 11:32 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it.

## Critical

Critical, because:

- CVSS score 9.9: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected products, as the CNA wrote them

- Vendor: Siemens. Product: SIMATIC PCS 7 V8.2.
  - affected: `All versions`
  - Other versions: unknown
- Vendor: Siemens. Product: SIMATIC PCS 7 V9.0.
  - affected: `All versions < V9.0 SP3 UC04`
  - Other versions: unknown
- Vendor: Siemens. Product: SIMATIC PCS 7 V9.1.
  - affected: `All versions < V9.1 SP1`
  - Other versions: unknown
- Vendor: Siemens. Product: SIMATIC WinCC V15 and earlier.
  - affected: `All versions < V15 SP1 Update 7`
  - Other versions: unknown
- Vendor: Siemens. Product: SIMATIC WinCC V16.
  - affected: `All versions < V16 Update 5`
  - Other versions: unknown
- Vendor: Siemens. Product: SIMATIC WinCC V17.
  - affected: `All versions < V17 Update 2`
  - Other versions: unknown
- Vendor: Siemens. Product: SIMATIC WinCC V7.4.
  - affected: `All versions < V7.4 SP1 Update 19`
  - Other versions: unknown
- Vendor: Siemens. Product: SIMATIC WinCC V7.5.
  - affected: `All versions < V7.5 SP2 Update 5`
  - Other versions: unknown

## Not analysed yet

We haven’t published our own analysis of this CVE. If a person reviews it, this page will say what’s affected and what has to be true for it to matter.

## Severity and exploitation

- 9.9 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:O/RC:C`, from CNA (siemens)

- **CISA KEV:** Not listed.
- **EPSS:** 0.013, the 70th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

This record came from the full history of the CVE Program, published 9 Nov 2021. New records show when each source confirmed them.

## Sources

- [CVE List: CVE-2021-40358](https://www.cve.org/CVERecord?id=CVE-2021-40358)
- [NVD: CVE-2021-40358](https://nvd.nist.gov/vuln/detail/CVE-2021-40358)

### References from the CNA

- <https://cert-portal.siemens.com/productcert/pdf/ssa-840188.pdf>

Facts on this page come from the CVE List as the CNA published them, with CVSS from the sources named above, CISA KEV and FIRST EPSS. Vendors, products and versions are shown as the CNA wrote them. We don’t reproduce the CVE’s description.

## Check whether this affects you

This CVE names a vendor and product rather than a package, so the lockfile check doesn’t match it. Compare the affected versions above with what you run.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), `get_advisory` returns this record and `search_advisories` finds related ones. Setup: <https://agentprime.io/mcp.md>
- As JSON: <https://api.agentprime.io/v1/advisories/CVE-2021-40358>
- Everything that needs attention now: <https://agentprime.io/advisories/critical.md>

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The web page: <https://agentprime.io/advisories/CVE-2021-40358/>. Everything for agents: <https://agentprime.io/llms.txt>.