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Full vulnerability report · 2023
CVE-2023-41913High confidence

strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy

Unknown · Unknown

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.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 2.31% for the current model date.

Compensating controls

  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  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: Within 3 daysRemediation target: Within 90 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.

Distribution package intelligence

Release-specific package status

Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

7 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainstrongswanVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.5.9.12-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · mainstrongswanVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.5.9.12-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · mainstrongswanVendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.5.9.12-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourcestrongswanVendor fix publishedDebian records a fixed source-package version for this release.5.9.12-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian bookwormbookworm · sourcestrongswanVendor fix publishedDebian records a fixed source-package version for this release.5.9.8-5+deb12u1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian forkyforky · sourcestrongswanVendor fix publishedDebian records a fixed source-package version for this release.5.9.12-1Debian Security Tracker ↗Source updated 5 Oct 2026
Debian sidsid · sourcestrongswanVendor fix publishedDebian records a fixed source-package version for this release.5.9.12-1Debian Security Tracker ↗Source updated 5 Oct 2026
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-2023-46391

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 actionWithin 72 hours

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

Fix not verified
01

What, why and how

strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. The earliest affected version is 5.3.0. An attack can occur via a crafted IKE_SA_INIT message.

What

strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. The earliest affected version is 5.3.0. An attack can occur via a crafted IKE_SA_INIT message.

Why

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code execution via a DH public value that exceeds the internal buffer in charon-tkm's DH proxy. The earliest affected version is 5.3.0. An attack can occur via a crafted IKE_SA_INIT message.

Why

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. 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
a network path → Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') → execute code or commands in the affected security context
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-120 ↗

CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow'). The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

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
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.
NetworkUnauthenticatedRemote code executionCWE-120
A

Official authority intelligence

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

BSI · German · WID-SEC-2023-2972strongSwan: Schwachstelle ermöglicht Codeausführung und DoS

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in strongSwan ausnutzen, um beliebigen Code auszuführen oder einen Denial-of-Service-Zustand zu verursachen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20231213Security Bulletin 13 Dec 2023

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 13 Dec 2023, published on 13 December 2023. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0297Multiples vulnérabilités dans Juniper

Record?id=CVE-2023-3446 Référence CVE CVE-2023-3592 https://www.cve.org/CVERecord?id=CVE-2023-3592 Référence CVE CVE-2023-36054 https://www.cve.org/CVERecord?id=CVE-2023-36054 Référence CVE CVE-2023-38408 https://www.cve.org/CVERecord?id=CVE-2023-38408 Référence CVE CVE-2023-38545 https://www.cve.org/CVERecord?id=CVE-2023-38545 Référence CVE CVE-2023-38546 https://www.cve.org/CVERecord?id=CVE-2023-38546 Référence CVE CVE-2023-3978 https://www.cve.org/CVERecord?id=CVE-2023-3978 Référence CVE CVE-2023-39975 https://www.cve.org/CVERecord?id=CVE-2023-39975 Référence CVE CVE-2023-40217 https://www.cve.org/CVERecord?id=CVE-2023-40217 Référence CVE CVE-2023-41913 https://www.cve.org/CVERecord?id=CVE-2023-41913 Référence CVE CVE-2023-43804 https://www.cve.org/CVERecord?id=CVE-2023-43804 Référence CVE CVE-2023-44487 https://www.cve.org/CVERecord?id=CVE-2023-44487 Référence CVE CVE-2023-46218 https://www.cve.org/CVERecord?id=CVE-2023-46218 Référence CVE CVE-2023-4785 https://www.cve.org/CVERecord?id=CVE-2023-4785 Référence CVE CVE-2023-4806 https://www.cve.org/CVERecord?id=CVE-2023-4806 Référence CVE CVE-2023-4807 https://www.cve.org/CVERecord?id=CVE-2023-4807 Référence CVE CVE-2023-48795 https://www.cve.org/CVERecord?id=CVE-2023-48795 Référence CVE CVE-2023-49083 https://www.cve.org/CVERecord?id=CVE-20

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0967Vulnérabilité dans les produits StrongSwan

Une vulnérabilité a été découverte dans les produits StrongSwan . Elle permet à un attaquant de provoquer une exécution de code arbitraire à distance.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2023-019090strongSwan における古典的バッファオーバーフローの脆弱性

strongSwan には、古典的バッファオーバーフローの脆弱性が存在します。

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 not verified
Affected
n/a
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
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 7 Dec 2023 · Last source change 18 Dec 2025, 15:29 UTC · CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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-2023-46391
Product sourceUnavailable
Remediation sourceCVE/CNA references
CWE sourceCISA ADP
NVD statusNVD modified after enrichment

Missing structured fields: affected product. Missing data is not evidence of low risk; review the primary advisory.

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
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-2023-41913 · cve.blacktree.nl