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 1.38% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2021
CVE-2021-31571High confidence
The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation
Unknown · Unknown
9.8CriticalCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productCritical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityCritical→Operational priority:Critical, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Unknown Unknown and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- SICK PSIRT: 1 affected or under-investigation product state without a fixed product state in the same current advisory
Direct vendor intelligence
2 currentAuthoritative 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.
SCA-2025-0003 · CSAF 2.0 · revision 4 · finalSICK PSIRTFreeRTOS Vulnerabilities have no impact on SICK Products
The vendor explicitly states that these products are not affected by this CVE.
- SICK deTem4 with Firmware 1.02 up to 1.3.0
- SICK deTem4 A/P with Firmware 1.02 up to 1.32.0
- SICK deTec4 with Firmware 1.05 up to 1.51.0
- SICK scanGrid2 with Firmware 1.10 up to 1.15
- SICK DMM4 with Firmware 1.2.0 up to 1.4.0
- SICK safeVisionary2 all Firmware versions
- SICK FXL1 with Firmware 1.6.0 up to 1.21.0
- SICK SE1 with Firmware 1.16.0 up to 1.17.0
- SICK deTem4 LT Muting A/P with Firmware 1.10
- SICK deTem4 Core A/P with Firmware 1.04 up to 1.10
- SICK deTem2 Core A/P with Firmware 1.04 up to 1.10
- SICK ANM58B all Firmware versions
- Summary
- The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation.
- Remediation
- No remediation text is recorded.
SCA-2024-0004 · CSAF 2.0 · revision 2 · finalSICK PSIRTThird party vulnerabilities in SICK CDE-100
The vendor has not yet reached a final affected or unaffected determination for these products.
- SICK CDE-100 all Firmware versions
- Summary
- The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation.
- Remediation
- SICK is still investigating if the CDE-100 is affected by this vulnerability. Please make sure that you apply general security practices when operating the CDE-100 like network segmentation. The following General Security Practices and Operating Guidelines could mitigate the associated security risk.
Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded. Verified remediation exists for at least one product or source, but 1 structured product or package state remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation.
What
The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation.
Why
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
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
The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation.
Why
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
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 No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 → Integer Overflow or Wraparound → 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-190 ↗
CWE-190: Integer Overflow or Wraparound. The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
- 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:HCommon 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.
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
- n/a
- 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
- SICK is still investigating if the CDE-100 is affected by this vulnerability. Please make sure that you apply general security practices when operating the CDE-100 like network segmentation. The following General Security Practices and Operating Guidelines could mitigate the associated security risk.
04
Evidence and provenance
Published 22 Apr 2021 · Last source change 3 Aug 2024, 23:03 UTC · CWE-190 · Integer Overflow or Wraparound
CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2021-18465
Product sourceUnavailable
Remediation sourceVendor CSAF · SICK PSIRT
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
View recent updates ↗What changed after publication
- Vendor guidanceAuthoritative vendor guidance changed: added remediation: sick.com/special_information_sick_operating_guidelines_cybersecurity_by_sick_en_im0106719.pdf; removed remediation: sick.com/psirt.SICK PSIRT ↗
- Before
- remediation: sick.com/psirt
- After
- remediation: sick.com/special_information_sick_operating_guidelines_cybersecurity_by_sick_en_im0106719.pdf
- Vendor guidanceAuthoritative vendor guidance changed: added remediation: sick.com/special_information_sick_operating_guidelines_cybersecurity_by_sick_en_im0106719.pdf; removed remediation: nvd.nist.gov/CVE-2021-31571.SICK PSIRT ↗
- Before
- remediation: nvd.nist.gov/CVE-2021-31571
- After
- remediation: sick.com/special_information_sick_operating_guidelines_cybersecurity_by_sick_en_im0106719.pdf
CVE published
Fixed release or patch reference recorded
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.