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Full vulnerability report · 2021
CVE-2021-33716High confidence

A vulnerability has been identified in SIMATIC CP 1543-1 (incl

Siemens · SIMATIC CP 1543-1 (incl. SIPLUS variants)

6.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
SSA-535997 · CSAF 2.0 · revision 2 · finalSiemens ProductCERTSSA-535997: Cleartext Storage of Sensitive Information in Multiple SIMATIC Products
2 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SIMATIC CP 1543-1 (incl. SIPLUS variants)
  • SIMATIC CP 1545-1
Summary
An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.
Remediation
Update to V3.0 or later version and migrate the TIA Portal engineering project to V17.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-20393

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

A vulnerability has been identified in SIMATIC CP 1543-1 (incl. SIPLUS variants) (All versions < V3.0), SIMATIC CP 1545-1 (All versions < V1.1). An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.

What

A vulnerability has been identified in SIMATIC CP 1543-1 (incl. SIPLUS variants) (All versions < V3.0), SIMATIC CP 1545-1 (All versions < V1.1). An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.

Why

The product stores sensitive information in cleartext within a resource that might be accessible to another control sphere.

How

An attacker operating through the affected interface may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.

What

A vulnerability has been identified in SIMATIC CP 1543-1 (incl. SIPLUS variants) (All versions < V3.0), SIMATIC CP 1545-1 (All versions < V1.1). An attacker with access to the subnet of the affected device could retrieve sensitive information stored in cleartext.

Why

The product stores sensitive information in cleartext within a resource that might be accessible to another control sphere.

How

An attacker operating through the affected interface may attempt exploitation without authentication or user interaction. If successful, the issue may obtain information outside the intended access boundary.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
the affected interface → Cleartext Storage of Sensitive Information → obtain information outside the intended access boundary
Attack surface
Unspecified
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-312 ↗

CWE-312: Cleartext Storage of Sensitive Information. The product stores sensitive information in cleartext within a resource that might be accessible to another control sphere.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVAdjacentAttack vector: The attacker must be on an adjacent or logically close network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.INoneIntegrity impact: No direct loss is represented by this metric.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
UnauthenticatedCWE-312
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

CERT-FR · French · CERTFR-2021-AVI-706Multiples vulnérabilités dans les produits Siemens

ord?id=CVE-2016-10011 Référence CVE CVE-2016-10708 https://www.cve.org/CVERecord?id=CVE-2016-10708 Référence CVE CVE-2019-10941 https://www.cve.org/CVERecord?id=CVE-2019-10941 Référence CVE CVE-2020-36475 https://www.cve.org/CVERecord?id=CVE-2020-36475 Référence CVE CVE-2020-36478 https://www.cve.org/CVERecord?id=CVE-2020-36478 Référence CVE CVE-2020-7461 https://www.cve.org/CVERecord?id=CVE-2020-7461 Référence CVE CVE-2021-25665 https://www.cve.org/CVERecord?id=CVE-2021-25665 Référence CVE CVE-2021-27391 https://www.cve.org/CVERecord?id=CVE-2021-27391 Référence CVE CVE-2021-31891 https://www.cve.org/CVERecord?id=CVE-2021-31891 Référence CVE CVE-2021-33716 https://www.cve.org/CVERecord?id=CVE-2021-33716 Référence CVE CVE-2021-33719 https://www.cve.org/CVERecord?id=CVE-2021-33719 Référence CVE CVE-2021-33720 https://www.cve.org/CVERecord?id=CVE-2021-33720 Référence CVE CVE-2021-33737 https://www.cve.org/CVERecord?id=CVE-2021-33737 Référence CVE CVE-2021-37173 https://www.cve.org/CVERecord?id=CVE-2021-37173 Référence CVE CVE-2021-37174 https://www.cve.org/CVERecord?id=CVE-2021-37174 Référence CVE CVE-2021-37175 https://www.cve.org/CVERecord?id=CVE-2021-37175 Référence CVE CVE-2021-37176 https://www.cve.org/CVERecord?id=CVE-2021-37176 Référence CVE CVE-2021-37177 https://www.cve.org/CVERecord?id=

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
SIMATIC CP 1543-1 (incl. SIPLUS variants); SIMATIC CP 1545-1
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Update to V3.0 or later version and migrate the TIA Portal engineering project to V17.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 14 Sept 2021 · Last source change 3 Aug 2024, 23:58 UTC · CWE-312 · Cleartext Storage of Sensitive Information

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-20393
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2021-20393↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-33716 · cve.blacktree.nl