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Full vulnerability report · 2024
CVE-2023-32736High confidence

Siemens SIMATIC S7-PLCSIM V16 — Deserialization of Untrusted Data

Siemens · SIMATIC S7-PLCSIM V16

Official source article: Siemens SSA-871035 ↗. Check the applicable product and release in the original source.

7.0HighCVSS 4.0
Recommended action
Patch only the product branches with a verified fix

High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 30 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:Medium, lowered one band.downgradedsince 14 Jan 2025

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • Exploitation requires an existing local or physical foothold with privileges.
  • EPSS is 0.22% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict local access and enforce least privilege on affected hosts.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Siemens SIMATIC S7-PLCSIM V16 and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: As exposure requiresRemediation target: Within 365 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 30 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

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-871035 · CSAF 2.0 · revision 2 · interimSiemens ProductCERTSSA-871035: Session-Memory Deserialization Vulnerability in Siemens Engineering Platforms Before V19
30 known affected

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

  • SIMATIC S7-PLCSIM V16
  • SIMATIC S7-PLCSIM V17
  • SIMATIC STEP 7 Safety V16
  • SIMATIC STEP 7 Safety V17
  • SIMATIC STEP 7 Safety V18
  • SIMATIC STEP 7 V16
  • SIMATIC STEP 7 V17
  • SIMATIC STEP 7 V18
  • SIMATIC WinCC Unified V16
  • SIMATIC WinCC Unified V17
  • SIMATIC WinCC Unified V18
  • SIMATIC WinCC V16
Summary
Affected products do not properly sanitize user-controllable input when parsing user settings. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application.
Remediation
Update to V17 Update 8 or later version
Optional official sources

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

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

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-2023-36961

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 actionPatch only the product branches with a verified fix

High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 30 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Fix availability varies by product
01

What, why and how

A vulnerability has been identified in SIMATIC S7-PLCSIM V16 (All versions), SIMATIC S7-PLCSIM V17 (All versions), SIMATIC STEP 7 Safety V16 (All versions), SIMATIC STEP 7 Safety V17 (All versions < V17 Update 8), SIMATIC STEP 7 Safety V18 (All versions < V18 Update 5), SIMATIC STEP 7 V16 (All versions), SIMATIC STEP 7 V17 (All versions < V17 Update 8), SIMATIC STEP 7 V18 (All versions < V18 Update 5), SIMATIC WinCC Unified V16 (All versions), SIMATIC WinCC Unified V17 (All versions < V17 Update 8), SIMATIC WinCC Unified V18 (All versions < V18 SP5), SIMATIC WinCC V16 (All versions), SIMATIC WinCC V17 (All versions < V17 Update 8), SIMATIC WinCC V18 (All versions < V18 SP5), SIMOCODE ES V16 (All versions), SIMOCODE ES V17 (All versions < V17 Update 8), SIMOCODE ES V18 (All versions), SIMOTION SCOUT TIA V5.4 SP1 (All versions), SIMOTION SCOUT TIA V5.4 SP3 (All versions), SIMOTION SCOUT TIA V5.5 SP1 (All versions), SINAMICS Startdrive V16 (All versions), SINAMICS Startdrive V17 (All versions), SINAMICS Startdrive V18 (All versions), SIRIUS Safety ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Safety ES V18 (TIA Portal) (All versions), SIRIUS Soft Starter ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Soft Starter ES V18 (TIA Portal) (All versions), TIA Portal Cloud V16 (All versions), TIA Portal Cloud V17 (All versions < V4.6.0.1), TIA Portal Cloud V18 (All versions < V4.6.1.0). Affected products do not properly sanitize user-controllable input when parsing user settings. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application.

What

A vulnerability has been identified in SIMATIC S7-PLCSIM V16 (All versions), SIMATIC S7-PLCSIM V17 (All versions), SIMATIC STEP 7 Safety V16 (All versions), SIMATIC STEP 7 Safety V17 (All versions < V17 Update 8), SIMATIC STEP 7 Safety V18 (All versions < V18 Update 5), SIMATIC STEP 7 V16 (All versions), SIMATIC STEP 7 V17 (All versions < V17 Update 8), SIMATIC STEP 7 V18 (All versions < V18 Update 5), SIMATIC WinCC Unified V16 (All versions), SIMATIC WinCC Unified V17 (All versions < V17 Update 8), SIMATIC WinCC Unified V18 (All versions < V18 SP5), SIMATIC WinCC V16 (All versions), SIMATIC WinCC V17 (All versions < V17 Update 8), SIMATIC WinCC V18 (All versions < V18 SP5), SIMOCODE ES V16 (All versions), SIMOCODE ES V17 (All versions < V17 Update 8), SIMOCODE ES V18 (All versions), SIMOTION SCOUT TIA V5.4 SP1 (All versions), SIMOTION SCOUT TIA V5.4 SP3 (All versions), SIMOTION SCOUT TIA V5.5 SP1 (All versions), SINAMICS Startdrive V16 (All versions), SINAMICS Startdrive V17 (All versions), SINAMICS Startdrive V18 (All versions), SIRIUS Safety ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Safety ES V18 (TIA Portal) (All versions), SIRIUS Soft Starter ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Soft Starter ES V18 (TIA Portal) (All versions), TIA Portal Cloud V16 (All versions), TIA Portal Cloud V17 (All versions < V4.6.0.1), TIA Portal Cloud V18 (All versions < V4.6.1.0). Affected products do not properly sanitize user-controllable input when parsing user settings. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application.

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

What

A vulnerability has been identified in SIMATIC S7-PLCSIM V16 (All versions), SIMATIC S7-PLCSIM V17 (All versions), SIMATIC STEP 7 Safety V16 (All versions), SIMATIC STEP 7 Safety V17 (All versions < V17 Update 8), SIMATIC STEP 7 Safety V18 (All versions < V18 Update 5), SIMATIC STEP 7 V16 (All versions), SIMATIC STEP 7 V17 (All versions < V17 Update 8), SIMATIC STEP 7 V18 (All versions < V18 Update 5), SIMATIC WinCC Unified V16 (All versions), SIMATIC WinCC Unified V17 (All versions < V17 Update 8), SIMATIC WinCC Unified V18 (All versions < V18 SP5), SIMATIC WinCC V16 (All versions), SIMATIC WinCC V17 (All versions < V17 Update 8), SIMATIC WinCC V18 (All versions < V18 SP5), SIMOCODE ES V16 (All versions), SIMOCODE ES V17 (All versions < V17 Update 8), SIMOCODE ES V18 (All versions), SIMOTION SCOUT TIA V5.4 SP1 (All versions), SIMOTION SCOUT TIA V5.4 SP3 (All versions), SIMOTION SCOUT TIA V5.5 SP1 (All versions), SINAMICS Startdrive V16 (All versions), SINAMICS Startdrive V17 (All versions), SINAMICS Startdrive V18 (All versions), SIRIUS Safety ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Safety ES V18 (TIA Portal) (All versions), SIRIUS Soft Starter ES V17 (TIA Portal) (All versions < V17 Update 8), SIRIUS Soft Starter ES V18 (TIA Portal) (All versions), TIA Portal Cloud V16 (All versions), TIA Portal Cloud V17 (All versions < V4.6.0.1), TIA Portal Cloud V18 (All versions < V4.6.1.0). Affected products do not properly sanitize user-controllable input when parsing user settings. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application.

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

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
local access → Deserialization of Untrusted Data → execute code or commands in the affected security context
Attack surface
Local
Privileges required
Low: a basic authenticated account is required
User interaction
Passive interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-502 ↗

CWE-502: Deserialization of Untrusted Data. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRLowPrivileges required: The attacker needs basic user-level privileges.UIPassiveUser interaction: A user must unknowingly interact with the vulnerable system.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VAHighVulnerable-system availability: A successful attack can cause a major loss.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
Remote code executionCWE-502
A

Official authority intelligence

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

BSI · German · WID-SEC-2024-3416Siemens SIMATIC S7: Schwachstelle ermöglicht Codeausführung

Ein lokaler Angreifer kann eine Schwachstelle in Siemens SIMATIC S7 ausnutzen, um beliebigen Programmcode auszuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20241113Security Bulletin 13 Nov 2024

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 13 Nov 2024, published on 13 November 2024. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0968Multiples vulnérabilités dans les produits Siemens

De multiples vulnérabilités ont été découvertes dans les produits Siemens. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et une atteinte à la confidentialité des données.

Official advisory ↗
NCSC-NL · Dutch · NCSC-2024-0433Kwetsbaarheden verholpen in Siemens producten

De kwetsbaarheden stellen een kwaadwillende mogelijk in staat aanvallen uit te voeren die kunnen leiden tot de volgende categorieën schade: - Denial-of-Service (DoS) - Cross-Site-Scripting (XSS) - Manipulatie van gegevens - Omzeilen van een beveiligingsmaatregel - Omzeilen van authenticatie - (Remote) code execution (Administrator/Root rechten) - (Remote) code execution (Gebruikersrechten) - Toegang tot systeemgegevens - Verhoogde gebruikersrechten De kwaadwillende heeft hiervoor toegang nodig tot de productieomgeving. Het is goed gebruik een dergelijke omgeving niet publiek toegankelijk te hebben.

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.
Fix availability varies by product
Affected
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
Workaround
No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 12 Nov 2024 · Last source change 14 Jan 2025, 10:27 UTC · CWE-502 · Deserialization of Untrusted Data

CVE recordCVE.org · 5.1
CVSS sourceCNA
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-2023-36961
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCNA
NVD statusNVD not scheduled

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

Material change intelligence

What changed after publication

View recent updates ↗
  1. Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
    Before
    Awaiting fix
    After
    Mitigation available
    Siemens ProductCERT ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Remediation guidance recorded
ENISA EUVD · EUVD-2023-36961↗CVE authority or vendor reference · Siemens SSA-871035↗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-2023-32736 · cve.blacktree.nl