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Full vulnerability report · 2023
CVE-2023-28531High confidence

ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints

n/a · n/a

9.8CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Mitigation 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.

2 current
SSA-019113 · CSAF 2.0 · revision 2 · interimSiemens ProductCERTSSA-019113: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.6
5 known affected

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

  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.6
  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.6
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.6
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= V3.1.6
  • SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= V3.1.6
Summary
ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.
Remediation
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
SSA-082556 · CSAF 2.0 · revision 7 · interimSiemens ProductCERTSSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5
5 known affected

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

  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.5
  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.5
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.5
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= V3.1.5
  • SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= V3.1.5
Summary
ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.
Remediation
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
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-2023-32201

No EUVD known-exploited evidence

ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.

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
0.0
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Mitigation available
01

What, why and how

ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.

What

ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.

Why

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.

Why

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

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
a network path → Improper Access Control → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
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-284 ↗

CWE-284: Improper Access Control. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

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

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

AVNetworkAttack vector: The vulnerable component can be reached over a 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.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
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.
NetworkUnauthenticatedCWE-284
A

Official authority intelligence

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

ENISA EUVD · EUVD-2023-32201Official EUVD mapping

ssh-add in OpenSSH before 9.3 adds smartcard keys to ssh-agent without the intended per-hop destination constraints. The earliest affected version is 8.9.

Official EUVD record
BSI · German · WID-SEC-W-2024-1082Juniper JUNOS: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Juniper JUNOS im Zusammenhang mit OpenSSH ausnutzen, um Sicherheitsmaßnahmen zu umgehen, beliebigen Code auszuführen oder Dateien zu manipulieren.

Official advisory
BSI · German · WID-SEC-W-2023-0670OpenSSH: Mehrere Schwachstellen

Ein lokaler Angreifer kann mehrere Schwachstellen in OpenSSH ausnutzen, um Sicherheitsvorkehrungen zu umgehen oder einen Denial of Service Zustand herbeizuführen.

Official advisory
CERT-FR · French · CERTFR-2026-AVI-0880Multiples vulnérabilités dans les produits Siemens

juillet 2026 Bulletin de sécurité Siemens SSA-734552 du 14 juillet 2026 Bulletin de sécurité Siemens SSA-828211 du 14 juillet 2026 Une gestion de version détaillée se trouve à la fin de ce document. Risques Atteinte à la confidentialité des données Contournement de la politique de sécurité Déni de service à distance Exécution de code arbitraire à distance Non spécifié par l'éditeur Élévation de privilèges Systèmes affectés Desigo CC toutes versions Desigo CC toutes versions pour la vulnérabilité CVE-2025-15467 Desigo CC versions antérieures à 9.0.1 SIMATIC S7-1500 versions supérieures ou égales à 3.1.6 pour les vulnérabilités CVE-2021-41617, CVE-2023-28531, CVE-2023-51384, CVE-2023-52927, CVE-2024-26783, CVE-2024-27056, CVE-2024-28956, CVE-2024-36903, CVE-2024-36927, CVE-2024-42079, CVE-2024-46786, CVE-2024-47736, CVE-2024-47809, CVE-2024-49968, CVE-2024-49994, CVE-2024-49998, CVE-2024-50014, CVE-2024-50063, CVE-2024-50164, CVE-2024-50298, CVE-2024-53124, CVE-2024-53170, CVE-2024-54458, CVE-2024-56631, CVE-2024-56703, CVE-2024-56719, CVE-2024-57917, CVE-2024-57924, CVE-2024-57973, CVE-2024-57977, CVE-2024-57979, CVE-2024-58011, CVE-2024-58016, CVE-2024-58020, CVE-2024-58056, CVE-2024-58058, CVE-2024-58061, CVE-2024-58086, CVE-2025-21645, CVE-2025-21648, CVE-2025-21655, CVE-2025-21676, CVE-2025

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0492Multiples vulnérabilités dans les produits Siemens

LANCE XRM334 (2x230 V AC, 12xFO) (6GK5334-3TS01-4AR3) versions antérieures à V3.2 SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3) versions antérieures à V3.1 SCALANCE XRM334 (2x230 V AC, 8xFO) (6GK5334-2TS01-4AR3) versions antérieures à V3.2 SCALANCE XRM334 (2x230V AC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-4AR3) versions antérieures à V3.1 SCALANCE XRM334 (2x230V AC, 2x10G, 24xSFP, 8xSFP+) (6GK5334-5TS01-4AR3) versions antérieures à V3.2 SIMATIC S7-1500 versions supérieures ou égales àV3.1.5 pour les vulnérabilités CVE-2021-41617, CVE-2023-4527, CVE-2023-4806, CVE-2023-4911, CVE-2023-5363, CVE-2023-6246, CVE-2023-6779, CVE-2023-6780, CVE-2023-28531, CVE-2023-38545, CVE-2023-38546, CVE-2023-44487, CVE-2023-46218, CVE-2023-46219, CVE-2023-48795, CVE-2023-51384, CVE-2023-51385, CVE-2023-52927, CVE-2024-2961, CVE-2024-6119, CVE-2024-6387, CVE-2024-12133, CVE-2024-12243, CVE-2024-24855, CVE-2024-26596, CVE-2024-28085, CVE-2024-33599, CVE-2024-33600, CVE-2024-33601, CVE-2024-33602, CVE-2024-34397, CVE-2024-37370, CVE-2024-37371, CVE-2024-45490, CVE-2024-45491, CVE-2024-45492, CVE-2024-50246, CVE-2024-53166, CVE-2024-57977, CVE-2024-57996, CVE-2024-58005, CVE-2025-4373, CVE-2025-4598, CVE-2025-21701, CVE-2025-21702, CVE-2025-21712, CVE-2025-21724, CVE-2025-21728, CVE-2025-21745, CVE-2025-2175

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0585Multiples vulnérabilités dans les produits VMware

org/CVERecord?id=CVE-2021-41617 Référence CVE CVE-2022-1725 https://www.cve.org/CVERecord?id=CVE-2022-1725 Référence CVE CVE-2022-1771 https://www.cve.org/CVERecord?id=CVE-2022-1771 Référence CVE CVE-2022-1886 https://www.cve.org/CVERecord?id=CVE-2022-1886 Référence CVE CVE-2022-1897 https://www.cve.org/CVERecord?id=CVE-2022-1897 Référence CVE CVE-2022-2000 https://www.cve.org/CVERecord?id=CVE-2022-2000 Référence CVE CVE-2022-2042 https://www.cve.org/CVERecord?id=CVE-2022-2042 Référence CVE CVE-2022-46908 https://www.cve.org/CVERecord?id=CVE-2022-46908 Référence CVE CVE-2022-48624 https://www.cve.org/CVERecord?id=CVE-2022-48624 Référence CVE CVE-2023-28531 https://www.cve.org/CVERecord?id=CVE-2023-28531 Référence CVE CVE-2023-2953 https://www.cve.org/CVERecord?id=CVE-2023-2953 Référence CVE CVE-2023-39804 https://www.cve.org/CVERecord?id=CVE-2023-39804 Référence CVE CVE-2023-46218 https://www.cve.org/CVERecord?id=CVE-2023-46218 Référence CVE CVE-2023-46219 https://www.cve.org/CVERecord?id=CVE-2023-46219 Référence CVE CVE-2023-46246 https://www.cve.org/CVERecord?id=CVE-2023-46246 Référence CVE CVE-2023-4641 https://www.cve.org/CVERecord?id=CVE-2023-4641 Référence CVE CVE-2023-4806 https://www.cve.org/CVERecord?id=CVE-2023-4806 Référence CVE CVE-2023-4813 https://www.cve.org/CVERecord?id=CVE-202

Official advisory
CERT-FR · French · CERTFR-2023-AVI-1015Multiples vulnérabilités dans les produits Siemens

d?id=CVE-2023-26604 Référence CVE CVE-2023-27371 https://www.cve.org/CVERecord?id=CVE-2023-27371 Référence CVE CVE-2023-27533 https://www.cve.org/CVERecord?id=CVE-2023-27533 Référence CVE CVE-2023-27534 https://www.cve.org/CVERecord?id=CVE-2023-27534 Référence CVE CVE-2023-27535 https://www.cve.org/CVERecord?id=CVE-2023-27535 Référence CVE CVE-2023-27536 https://www.cve.org/CVERecord?id=CVE-2023-27536 Référence CVE CVE-2023-27537 https://www.cve.org/CVERecord?id=CVE-2023-27537 Référence CVE CVE-2023-27538 https://www.cve.org/CVERecord?id=CVE-2023-27538 Référence CVE CVE-2023-28484 https://www.cve.org/CVERecord?id=CVE-2023-28484 Référence CVE CVE-2023-28531 https://www.cve.org/CVERecord?id=CVE-2023-28531 Référence CVE CVE-2023-28831 https://www.cve.org/CVERecord?id=CVE-2023-28831 Référence CVE CVE-2023-29383 https://www.cve.org/CVERecord?id=CVE-2023-29383 Référence CVE CVE-2023-29469 https://www.cve.org/CVERecord?id=CVE-2023-29469 Référence CVE CVE-2023-29491 https://www.cve.org/CVERecord?id=CVE-2023-29491 Référence CVE CVE-2023-29499 https://www.cve.org/CVERecord?id=CVE-2023-29499 Référence CVE CVE-2023-2953 https://www.cve.org/CVERecord?id=CVE-2023-2953 Référence CVE CVE-2023-30901 https://www.cve.org/CVERecord?id=CVE-2023-30901 Référence CVE CVE-2023-31085 https://www.cve.org/CVERecord?id=CV

Official advisory
NCSC-NL · Dutch · NCSC-2025-0187Kwetsbaarheden 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) - Manipulatie van gegevens - Omzeilen van een beveiligingsmaatregel - Omzeilen van authenticatie - (Remote) code execution (root/admin rechten) - (Remote) code execution (Gebruikersrechten) - Toegang tot systeemgegevens - Toegang tot gevoelige gegevens - Spoofing 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.
Mitigation available
Affected
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= V3.1.6; SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= V3.1.6; SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= V3.1.6; SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= V3.1.6; SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= V3.1.6
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
04

Evidence and provenance

Published 17 Mar 2023 · Last source change 8 Sept 2026, 08:30 UTC · CWE-284 · Improper Access Control

CVE recordCVE.org · 5.2
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-2023-32201
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceCISA ADP
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
ENISA EUVD · EUVD-2023-32201↗Vendor CSAF · Siemens ProductCERT↗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-2023-28531 · cve.blacktree.nl