CVE-2021-20987

HIGHNVD 8.68.6—

8.6

A denial of service and memory corruption vulnerability was found in Hilscher EtherNet/IP Core V2 prior to V2.13.0.21that may lead to code injection through network or make devices crash without recovery.

CVSS v3: 8.6
EG Score: 8.6(medium)
EPSS: 59.0%
KEV: Not listed

Published

February 16, 2021

Last Modified

November 21, 2024

References (4)

info@certhttps://cert.vde.com/en-us/advisories/vde-2021-007
info@certhttps://kb.hilscher.com/pages/viewpage.action?pageId=108969480
af854a3a-2127-422b-91ae-364da2661108https://cert.vde.com/en-us/advisories/vde-2021-007
af854a3a-2127-422b-91ae-364da2661108https://kb.hilscher.com/pages/viewpage.action?pageId=108969480

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-787Out-of-bounds Write

Data Freshness Timeline

(refreshed 13× in last 7d / 20× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

2026-06-08 14:15 UTCEPSS rescore
2026-06-08 14:15 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-07 15:23 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-06 13:46 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 22:45 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:09 UTCEPSS rescore
2026-06-05 06:08 UTCEPSS rescore
2026-06-04 13:10 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-02 20:11 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-06-01 13:50 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 22:29 UTCEPSS rescore
2026-05-31 00:15 UTCEPSS rescore

Frequently asked(5)

What is CVE-2021-20987?

CVE-2021-20987 is a high vulnerability published on February 16, 2021. A denial of service and memory corruption vulnerability was found in Hilscher EtherNet/IP Core V2 prior to V2.13.0.21that may lead to code injection through network or make devices crash without recovery.

When was CVE-2021-20987 disclosed?

CVE-2021-20987 was first published in the National Vulnerability Database on February 16, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2021-20987 actively exploited?

CVE-2021-20987 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 59.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2021-20987?

CVE-2021-20987 has a CVSS v3 base score of 8.6 (NVD).

How do I remediate CVE-2021-20987?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-20987, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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CVE-2021-20987

📅 Published

🔄 Last Modified

🔗 References (4)

Weakness Classification(1)

Data Freshness Timeline

❓ Frequently asked(5)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2021-20987?

🔗 Related CVEs(same CWE)

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Published

Last Modified

References (4)

Frequently asked(5)

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