HOMEVULNERABILITIESCVE-2021-20987
HIGH

CVE-2021-20987

CWE-787Published: February 16, 2021· Updated: Jun 17, 2026

8.6
CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2021-20987 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 8.6.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

From a weakness classification perspective (CWE-787): Out-of-bounds write vulnerabilities can lead to data corruption, crashes, or arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeChanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected Vendors & Products

hilscher2 product(s)
ethernet\/ip adapter firmwareethernet\/ip adapter
pepperl-fuchs21 product(s)
wcs firmwarewcs3b-ls510wcs3b-ls510-omwcs3b-ls510dwcs3b-ls510d-omwcs3b-ls510dhwcs3b-ls510dh-omwcs3b-ls510hwcs3b-ls510h-ompxv100-f200-b25-v1d firmwarepxv100-f200-b25-v1dpxv100i-f200-b25-v1d firmware+9
Source: NVD CPE · 23 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

All References (4)

Quick Facts

CVE IDCVE-2021-20987
CVSS Score8.6 / 10
SeverityHIGH
WeaknessCWE-787
CISA KEVNo
Affected2 vendor(s)
PublishedFeb 16, 2021

Related CVEs (CWE-787)

Recommended Actions

  • Apply vendor patches immediately
  • Monitor CVE-2021-20987 in threat intel feeds
  • Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.