CVE-2021-37172

What it is

A vulnerability has been identified in SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (V4.5.0). Affected devices fail to authenticate against configured passwords when provisioned using TIA Portal V13. This could allow an attacker using TIA Portal V13 or later versions to bypass authentication and download arbitrary programs to the PLC. The vulnerability does not occur when TIA Portal V13 SP1 or any later version was used to provision the device.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

0.9% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-08-10 11:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:00 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.9% in the next 30 days (EPSS).
• Severity: 7.5 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-08-10 11:15 UTC

Last modified

2026-06-17 04:00 UTC

Exploit probability

0.9% · EPSS, next 30 days

Weakness

CWE-287 · Improper authentication

Record status

Modified

Affected

• Siemens Simatic s7-1200 Cpu Firmware 4.5.0
• Siemens Simatic Step 7 \(tia portal\) ≤ 13.0

Attack profile CVSS 3.1 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

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