CVE-2021-31893

7.8 HIGH 0.6% 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 V9.0 (All versions < V9.0 SP3), SIMATIC PDM (All versions < V9.2), SIMATIC STEP 7 V5.X (All versions < V5.6 SP2 HF3), SINAMICS STARTER (containing STEP 7 OEM version) (All versions < V5.4 HF2). The affected software contains a buffer overflow vulnerability while handling certain files that could allow a local attacker to trigger a denial-of-service condition or potentially lead to remote code execution.

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: 0.6% 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: 0.6% in the next 30 days (EPSS).
Severity: 7.8 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: 0.6% · EPSS, next 30 days
Weakness: CWE-120 · Classic buffer overflow
Record status: Modified

Affected

Siemens Simatic Pcs Firmware ≤ 8.2
Siemens Simatic Pcs Firmware 9.0
Siemens Simatic Pdm Firmware < 9.2
Siemens Simatic Step 7 Firmware ≤ 5.6
Siemens Sinamics Starter Firmware < 5.4
Siemens Sinamics Starter Firmware 5.4

Attack profile CVSS 3.1 · 7.8

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

Raw vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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-2021-31893.md and follow it. Check whether this project is affected by CVE-2021-31893. 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