CVE-2021-31894

8.8 HIGH 0.2% exploit odds Fix listed

What it is

A vulnerability has been identified in SIMATIC PCS 7 V8.2 and earlier (All versions), SIMATIC PCS 7 V9.X (All versions < V9.1 SP2), SIMATIC PDM (All versions < V9.2 SP2), SIMATIC STEP 7 V5.X (All versions < V5.7), SINAMICS STARTER (containing STEP 7 OEM version) (All versions < V5.4 SP2 HF1). A directory containing metafiles relevant to devices' configurations has write permissions. An attacker could leverage this vulnerability by changing the content of certain metafiles and subsequently manipulate parameters or behavior of devices that would be later configured by the affected software.

At a glance

Exploitability: Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2021-07-13 11:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 03:52 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 8.8 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2021-07-13 11:15 UTC
Last modified: 2026-06-17 03:52 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-732 · Incorrect permission assignment
Record status: Modified

Affected

Siemens Simatic Pcs 7 Firmware ≤ 8.2
Siemens Simatic Pcs 7 Firmware 9.0
Siemens Simatic Pdm Firmware
Siemens Simatic Step 7 Firmware < 5.7
Siemens Sinamics Starter Firmware < 5.4
Siemens Sinamics Starter Firmware 5.4

Attack profile CVSS 3.1 · 8.8

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
Availability: High

Raw vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-31894.md and follow it. Check whether this project is affected by CVE-2021-31894. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record