CVE-2021-40363

System takeover via brute-forced project-file credentials

Published Feb 9, 2022 · Updated Aug 4, 2024

Credential exposure in Siemens SIMATIC WinCC and PCS 7 allows local users to take over a host through an accessible project file. The affected component writes local-system-account credentials into that file and protects them with an outdated cipher. A local low-privileged user who can read the project file can brute-force and reuse the credentials to control the host.

CVSS severity5.5
Medium
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential exposure in Siemens SIMATIC WinCC and PCS 7 allows local users to take over a host through an accessible project file. The affected component writes local-system-account credentials into that file and protects them with an outdated cipher. A local low-privileged user who can read the project file can brute-force and reuse the credentials to control the host.

The record

CVE
CVE-2021-40363
Published
Feb 9, 2022
Updated
Aug 4, 2024
Vendor
Siemens
Product
SIMATIC WinCC
Classifications
CWE-538, T1552.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 9, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=All versions < V15 SP1 Update 7
  2. Affected versionversion=All versions < V16 Update 5
  3. Affected versionversion=All versions < V17 Update 2
  4. Affected versionversion=All versions <= V17 Update 4
  5. Affected versionversion=All versions < V7.4 SP1 Update 19
  6. Affected versionversion=All versions < V7.5 SP2 Update 6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SIMATIC WinCCversion=All versions < V15 SP1 Update 7; version=All versions < V16 Update 5; version=All versions < V17 Update 2; version=All versions <= V17 Update 4; version=All versions < V7.4 SP1 Update 19; version=All versions < V7.5 SP2 Update 6
Siemens · SIMATIC PCS 7version=All versions; version=All versions < V9.1 SP1

Published CVSS scores

5.5Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1NIST NVDAV:L/AC:L/Au:N/C:P/I:N/A:N
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-538Insertion of Sensitive Information into Externally-Accessible File or Directory
T1552.001Unsecured Credentials Credentials In Files

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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