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Fencer Intel
high 8.6

CVE-2021-21777 json

An information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development c…

published 5y ago modified 4mo ago also EUVD-2021-8949

cvss
8.6
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.7%
EPSS 1.7% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

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.

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Exploit prediction

1.67% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2021-1234 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 8.6 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD 3.1 10.0 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:H
NVD 2.0 9.4 AV:N/AC:L/Au:N/C:C/I:N/A:C

Affected products

  • n/a EIP Stack Group

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.