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Full vulnerability report · 2023
CVE-2021-31239High confidence

An issue found in SQLite SQLite3 v.3.35.4 that allows a remote attacker to cause a denial of service via the appendvfs.c function

Unknown · Unknown

Official source article: Siemens SSA-398330 ↗. Check the applicable product and release in the original source.

7.5HighCVSS 3.1
Recommended action
Patch only the product branches with a verified fix

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 6 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:Critical, raised one band.upgradedsince 5 May 2025

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 2.16% 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 6 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.

Distribution package intelligence

Release-specific package status

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

4 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
Debian trixietrixie · sourcesqlite3Vendor fix publishedDebian records a fixed source-package version for this release.3.36.0-2Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourcesqlite3Vendor fix publishedDebian records a fixed source-package version for this release.3.36.0-2Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourcesqlite3Vendor fix publishedDebian records a fixed source-package version for this release.3.36.0-2Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourcesqlite3Vendor fix publishedDebian records a fixed source-package version for this release.3.36.0-2Debian Security Tracker ↗Source updated 6 Oct 2026
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-398330 · CSAF 2.0 · revision 18 · interimSiemens ProductCERTSSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < 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)
  • SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)
  • SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)
  • SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)
Summary
An issue found in SQLite SQLite3 v.3.35.4 that could allow a remote attacker to cause a denial of service via the appendvfs.c function.
Remediation
Update to V3.1.5 or later version
SSA-472630 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-472630: Security Vulnerabilities Fixed in RUGGEDCOM CROSSBOW V5.4
1 known affected

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

  • RUGGEDCOM CROSSBOW
Summary
An issue found in SQLite SQLite3 v.3.35.4 that could allow a remote attacker to cause a denial of service via the appendvfs.c function.
Remediation
Update to V5.4 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-2021-18151

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 with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 6 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

An issue found in SQLite SQLite3 v.3.35.4 that allows a remote attacker to cause a denial of service via the appendvfs.c function.

What

An issue found in SQLite SQLite3 v.3.35.4 that allows a remote attacker to cause a denial of service via the appendvfs.c function.

Why

The product reads data past the end, or before the beginning, of the intended buffer.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

An issue found in SQLite SQLite3 v.3.35.4 that allows a remote attacker to cause a denial of service via the appendvfs.c function.

Why

The product reads data past the end, or before the beginning, of the intended buffer.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

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 Read → disrupt the affected service
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-125 ↗

CWE-125: Out-of-bounds Read. The product reads 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:N/I:N/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.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.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.
NetworkUnauthenticatedDenial of serviceCWE-125Public 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-2023-1614Tenable Security Nessus Network Monitor: Mehrere Schwachstellen

Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in Tenable Security Nessus Network Monitor ausnutzen, um beliebigen Code auszuführen, vertrauliche Informationen offenzulegen, einen Denial-of-Service-Zustand auszulösen und Daten zu manipulieren.

Official advisory ↗
BSI · German · WID-SEC-2023-1395NetApp ActiveIQ Unified Manager: Schwachstelle ermöglicht Denial of Service

Ein entfernter, anonymer Angreifer kann eine Schwachstelle in NetApp ActiveIQ Unified Manager ausnutzen, um einen Denial of Service Angriff durchzuführen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20230510Security Bulletin 10 May 2023

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 10 May 2023, published on 10 May 2023. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2025-AVI-1057Multiples vulnérabilités dans les produits VMware

d?id=CVE-2020-22916 Référence CVE CVE-2020-27618 https://www.cve.org/CVERecord?id=CVE-2020-27618 Référence CVE CVE-2020-28196 https://www.cve.org/CVERecord?id=CVE-2020-28196 Référence CVE CVE-2020-29562 https://www.cve.org/CVERecord?id=CVE-2020-29562 Référence CVE CVE-2021-20227 https://www.cve.org/CVERecord?id=CVE-2021-20227 Référence CVE CVE-2021-20266 https://www.cve.org/CVERecord?id=CVE-2021-20266 Référence CVE CVE-2021-24031 https://www.cve.org/CVERecord?id=CVE-2021-24031 Référence CVE CVE-2021-24032 https://www.cve.org/CVERecord?id=CVE-2021-24032 Référence CVE CVE-2021-27645 https://www.cve.org/CVERecord?id=CVE-2021-27645 Référence CVE CVE-2021-31239 https://www.cve.org/CVERecord?id=CVE-2021-31239 Référence CVE CVE-2021-32256 https://www.cve.org/CVERecord?id=CVE-2021-32256 Référence CVE CVE-2021-3326 https://www.cve.org/CVERecord?id=CVE-2021-3326 Référence CVE CVE-2021-33294 https://www.cve.org/CVERecord?id=CVE-2021-33294 Référence CVE CVE-2021-33574 https://www.cve.org/CVERecord?id=CVE-2021-33574 Référence CVE CVE-2021-3421 https://www.cve.org/CVERecord?id=CVE-2021-3421 Référence CVE CVE-2021-3521 https://www.cve.org/CVERecord?id=CVE-2021-3521 Référence CVE CVE-2021-35937 https://www.cve.org/CVERecord?id=CVE-2021-35937 Référence CVE CVE-2021-35938 https://www.cve.org/CVERecord?id=CVE-20

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

d?id=CVE-2021-23336 Référence CVE CVE-2021-27212 https://www.cve.org/CVERecord?id=CVE-2021-27212 Référence CVE CVE-2021-27218 https://www.cve.org/CVERecord?id=CVE-2021-27218 Référence CVE CVE-2021-27219 https://www.cve.org/CVERecord?id=CVE-2021-27219 Référence CVE CVE-2021-27645 https://www.cve.org/CVERecord?id=CVE-2021-27645 Référence CVE CVE-2021-28041 https://www.cve.org/CVERecord?id=CVE-2021-28041 Référence CVE CVE-2021-28153 https://www.cve.org/CVERecord?id=CVE-2021-28153 Référence CVE CVE-2021-28363 https://www.cve.org/CVERecord?id=CVE-2021-28363 Référence CVE CVE-2021-28861 https://www.cve.org/CVERecord?id=CVE-2021-28861 Référence CVE CVE-2021-31239 https://www.cve.org/CVERecord?id=CVE-2021-31239 Référence CVE CVE-2021-3177 https://www.cve.org/CVERecord?id=CVE-2021-3177 Référence CVE CVE-2021-32292 https://www.cve.org/CVERecord?id=CVE-2021-32292 Référence CVE CVE-2021-3326 https://www.cve.org/CVERecord?id=CVE-2021-3326 Référence CVE CVE-2021-33294 https://www.cve.org/CVERecord?id=CVE-2021-33294 Référence CVE CVE-2021-33560 https://www.cve.org/CVERecord?id=CVE-2021-33560 Référence CVE CVE-2021-33574 https://www.cve.org/CVERecord?id=CVE-2021-33574 Référence CVE CVE-2021-33910 https://www.cve.org/CVERecord?id=CVE-2021-33910 Référence CVE CVE-2021-3426 https://www.cve.org/CVERecord?id=CVE-2

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0633Multiples vulnérabilités dans les produits Siemens

emens ssa-975961 du 8 août 2023 https://cert-portal.siemens.com/productcert/html/ssa-975961.html Référence CVE CVE-2020-15795 https://www.cve.org/CVERecord?id=CVE-2020-15795 Référence CVE CVE-2020-27009 https://www.cve.org/CVERecord?id=CVE-2020-27009 Référence CVE CVE-2020-27736 https://www.cve.org/CVERecord?id=CVE-2020-27736 Référence CVE CVE-2020-27737 https://www.cve.org/CVERecord?id=CVE-2020-27737 Référence CVE CVE-2020-27738 https://www.cve.org/CVERecord?id=CVE-2020-27738 Référence CVE CVE-2020-28388 https://www.cve.org/CVERecord?id=CVE-2020-28388 Référence CVE CVE-2021-25677 https://www.cve.org/CVERecord?id=CVE-2021-25677 Référence CVE CVE-2021-31239 https://www.cve.org/CVERecord?id=CVE-2021-31239 Référence CVE CVE-2021-41544 https://www.cve.org/CVERecord?id=CVE-2021-41544 Référence CVE CVE-2022-25634 https://www.cve.org/CVERecord?id=CVE-2022-25634 Référence CVE CVE-2022-37971 https://www.cve.org/CVERecord?id=CVE-2022-37971 Référence CVE CVE-2022-39062 https://www.cve.org/CVERecord?id=CVE-2022-39062 Référence CVE CVE-2022-4304 https://www.cve.org/CVERecord?id=CVE-2022-4304 Référence CVE CVE-2022-45937 https://www.cve.org/CVERecord?id=CVE-2022-45937 Référence CVE CVE-2023-0286 https://www.cve.org/CVERecord?id=CVE-2023-0286 Référence CVE CVE-2023-24845 https://www.cve.org/CVERecord?id=CVE-

Official advisory ↗
CERT-FR · French · CERTFR-2023-AVI-0499Multiples vulnérabilités dans Tenable Nessus Network Monitor

ecord?id=CVE-2020-14155 Référence CVE CVE-2020-15358 https://www.cve.org/CVERecord?id=CVE-2020-15358 Référence CVE CVE-2020-24977 https://www.cve.org/CVERecord?id=CVE-2020-24977 Référence CVE CVE-2020-35525 https://www.cve.org/CVERecord?id=CVE-2020-35525 Référence CVE CVE-2020-35527 https://www.cve.org/CVERecord?id=CVE-2020-35527 Référence CVE CVE-2020-7595 https://www.cve.org/CVERecord?id=CVE-2020-7595 Référence CVE CVE-2020-9327 https://www.cve.org/CVERecord?id=CVE-2020-9327 Référence CVE CVE-2021-20227 https://www.cve.org/CVERecord?id=CVE-2021-20227 Référence CVE CVE-2021-30560 https://www.cve.org/CVERecord?id=CVE-2021-30560 Référence CVE CVE-2021-31239 https://www.cve.org/CVERecord?id=CVE-2021-31239 Référence CVE CVE-2021-3517 https://www.cve.org/CVERecord?id=CVE-2021-3517 Référence CVE CVE-2021-3518 https://www.cve.org/CVERecord?id=CVE-2021-3518 Référence CVE CVE-2021-3537 https://www.cve.org/CVERecord?id=CVE-2021-3537 Référence CVE CVE-2021-3541 https://www.cve.org/CVERecord?id=CVE-2021-3541 Référence CVE CVE-2021-36690 https://www.cve.org/CVERecord?id=CVE-2021-36690 Référence CVE CVE-2021-3672 https://www.cve.org/CVERecord?id=CVE-2021-3672 Référence CVE CVE-2021-45346 https://www.cve.org/CVERecord?id=CVE-2021-45346 Référence CVE CVE-2022-22576 https://www.cve.org/CVERecord?id=CVE-2022-2

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2021-020660SQLite における境界外読み取りに関する脆弱性

SQLite には、境界外読み取り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
Update to V3.1.5 or later version
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
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 9 May 2023 · Last source change 5 May 2025, 16:53 UTC · CWE-125 · Out-of-bounds Read

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-2021-18151
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
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 ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    n/a · 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.
    After
    n/a · Fixed: Update to V3.1.5 or later version
    Siemens ProductCERT ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2021-18151↗Siemens ProductCERT security advisory · Siemens SSA-398330↗CISA Vulnrichment SSVC evidence↗CVE authority or vendor reference↗Mitigation reference↗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-2021-31239 · cve.blacktree.nl