What is CVE-2021-27500?

CVE-2021-27500 is a high-severity vulnerability in Eipstackgroup Opener Ethernet/ip, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2022-05-12.

How severe is CVE-2021-27500?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Eipstackgroup Opener Ethernet/ip

CVE-2021-27500

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.

Published 2022-05-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.013 (69.8th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 69.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: +0.000

Affected products

Eipstackgroup Opener Ethernet/ip — versions unspecified
Opener Project

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

www.cisa.gov/uscert/ics/advisories/icsa-21-105-02 (US Government Resource, Third Party Advisory)
github.com/EIPStackGroup/OpENer (Third Party Advisory)

Frequently asked questions

What is CVE-2021-27500?: CVE-2021-27500 is a high-severity vulnerability in Eipstackgroup Opener Ethernet/ip, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2022-05-12.
How severe is CVE-2021-27500?: High severity. CVSS v3 base score is 7.5 out of 10.