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Full vulnerability report · 2021
CVE-2016-20009High confidence

A DNS client stack-based buffer overflow in ipdnsc_decode_name() affects Wind River VxWorks 6.5 through 7

Unknown · Unknown

9.8CriticalCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

Critical technical impact with a remotely reachable, unauthenticated path and a public exploit reference; no CISA KEV confirmation is currently recorded. Verified remediation exists for at least one product or source, but 7 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 severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • A structured source references public exploit or proof-of-concept material.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 1.86% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Unknown Unknown 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: 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.

Cross-source reconciliation

Remediation availability differs by product scope

Verified remediation exists for at least one product or source, but 7 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-553445 · CSAF 2.0 · revision 1 · finalSiemens ProductCERTSSA-553445: DNS "Name:Wreck" Vulnerabilities in Multiple Siemens Energy AGT and SGT solutions
7 known affected

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

  • SGT-100
  • SGT-200
  • SGT-300
  • SGT-400
  • SGT-A20
  • SGT-A35
  • SGT-A65
Summary
** UNSUPPORTED WHEN ASSIGNED ** A DNS client stack-based buffer overflow in ipdnsc_decode_name() affects Wind River VxWorks 6.5 through 7. NOTE: This vulnerability only affects products that are no longer supported by the maintainer.
Remediation
As only Rockwell Automation / Allen Bradley components are affected, please see Rockwell Security Advisory PN1564 for affected parts and software/firmware updates. Some updates may not be compatible with other components in the system. Contact Siemens Energy for further support.
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-2016-3097

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

Critical technical impact with a remotely reachable, unauthenticated path and a public exploit reference; no CISA KEV confirmation is currently recorded. Verified remediation exists for at least one product or source, but 7 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 DNS client stack-based buffer overflow in ipdnsc_decode_name() affects Wind River VxWorks 6.5 through 7. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

What

A DNS client stack-based buffer overflow in ipdnsc_decode_name() affects Wind River VxWorks 6.5 through 7. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

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

A DNS client stack-based buffer overflow in ipdnsc_decode_name() affects Wind River VxWorks 6.5 through 7. NOTE: This vulnerability only affects products that are no longer supported by the maintainer

Why

A bounds error lets data be written beyond the intended memory region, potentially corrupting control data.

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.
Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path
a network path → Out-of-bounds Write → 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-787 ↗

CWE-787: Out-of-bounds Write. The product writes data past the end, or before the beginning, of the intended 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
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-787Public exploit reference
A

Official authority intelligence

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

BSI · German · WID-SEC-2023-1986NAME:WRECK: Mehrere Schwachstellen in TCP/IP Stacks

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Siemens Nucleus Net, Siemens Nucleus RTOS, Microsoft Azure RTOS NetX und Wind River VxWorks ausnutzen, um beliebigen Programmcode mit Administratorrechten auszuführen oder einen Denial of Service zu verursachen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20210317Security Bulletin 17 Mar 2021

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 17 Mar 2021, published on 17 March 2021. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2021-AVI-608Multiples vulnérabilités dans les produits Siemens

emens.com/productcert/pdf/ssa-679335.pdf Bulletin de sécurité Siemens ssa-756744 du 10 août 2021 https://cert-portal.siemens.com/productcert/pdf/ssa-756744.pdf Bulletin de sécurité Siemens ssa-818688 du 10 août 2021 https://cert-portal.siemens.com/productcert/pdf/ssa-818688.pdf Bulletin de sécurité Siemens ssa-830194 du 10 août 2021 https://cert-portal.siemens.com/productcert/pdf/ssa-830194.pdf Bulletin de sécurité Siemens ssa-865327 du 10 août 2021 https://cert-portal.siemens.com/productcert/pdf/ssa-865327.pdf Bulletin de sécurité Siemens ssa-938030 du 10 août 2021 https://cert-portal.siemens.com/productcert/pdf/ssa-938030.pdf Référence CVE CVE-2016-20009 https://www.cve.org/CVERecord?id=CVE-2016-20009 Référence CVE CVE-2020-12357 https://www.cve.org/CVERecord?id=CVE-2020-12357 Référence CVE CVE-2020-12358 https://www.cve.org/CVERecord?id=CVE-2020-12358 Référence CVE CVE-2020-12360 https://www.cve.org/CVERecord?id=CVE-2020-12360 Référence CVE CVE-2020-24486 https://www.cve.org/CVERecord?id=CVE-2020-24486 Référence CVE CVE-2020-24506 https://www.cve.org/CVERecord?id=CVE-2020-24506 Référence CVE CVE-2020-24507 https://www.cve.org/CVERecord?id=CVE-2020-24507 Référence CVE CVE-2020-24511 https://www.cve.org/CVERecord?id=CVE-2020-24511 Référence CVE CVE-2020-24512 https://www.cve.org/CVERecord?id=

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2016-009699Wind River VxWorks における境界外書き込みに関する脆弱性

** サポート外 ** 本件は、サポートされていない製品における脆弱性です。 Wind River VxWorks には、境界外書き込みに関する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 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. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 11 Mar 2021 · Last source change 6 Aug 2024, 03:47 UTC · CWE-787 · Out-of-bounds Write

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-2016-3097
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceNIST NVD
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 ↗
  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-2016-3097↗Siemens ProductCERT security advisory↗Public exploit 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-2016-20009 · cve.blacktree.nl