CVE-2021-21777

highpriority · track · 41EPSS 0.017 · 77 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

1.67% (77th) EPSS

CVSS 9.4 · high

Is it mine?

2 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. A specially crafted network request can lead to an out-of-bounds read.

cvss

Technical severity, 0–10. One row per scoring source.

10.0

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.6–10

v2.09.4highAV:N/AC:L/Au:N/C:C/I:N/A:Cprimary · NVD / NIST USexploitability 10 · impact 9.2

v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.8

v3.08.6highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · ENISA EU

v3.08.6highCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hsecondary · talos-cna@cisco.com USexploitability 3.9 · impact 4

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-125USprimary

affected products (2)

Products and version ranges known to be affected.

n/a EIP Stack Group≤ EIP Stack Group OpENer 2.3 ,EIP Stack Group OpENer development commit 8c73bf3enisa_euvdEU
opener project opener= 2.3nvdUScpe:2.3:a:opener_project:opener:*:*:*:*:*:*:*:*

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-06-17modified 2026-06-17

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+11870 more

references (5)

External citations — patches, advisories, analysis.

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