Home/CVE/A specifically crafted packet sent by an attacker to EIPStackGroup OpENer EtherNet/IP commits and versions prior to Feb
CVE

CVE-2021-27500

A specifically crafted packet sent by an attacker to EIPStackGroup OpENer EtherNet/IP commits and versions prior to Feb

A specifically crafted packet sent by an attacker to EIPStackGroup OpENer EtherNet/IP commits and versions prior to Feb 10, 2021 may result in a denial-of-service condition.

HIGH · CVSS 7.5 EPSS 0.00136
Schedule remediation
  • SSVC automatable: yes - attacks can be scripted at scale
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-617Reachable Assertion
▤

Affected Products & Versions

1
opener project opener<= 2.3
▣

Scoring & Timeline

7.5
HIGH · CVSS v3.1 · ics-cert@hq.dhs.gov
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD12 May 2022 · 08:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

2
cisa-csafcisa-csaf-csaf_files-OT-white-2021-icsa-21-105-02
cisa-csafcisa-csaf-csaf_files-OT-white-2025-icsa-25-273-02
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/EIPStackGroup/OpENerThird Party Advisory
https://www.cisa.gov/uscert/ics/advisories/icsa-21-105-02Third Party AdvisoryUS Government Resource
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