CVE-2021-27482Public exploitNetwork attack vector

Stack data disclosure via unchecked CPF item count

Published May 12, 2022 · Updated Apr 16, 2025

Out-of-bounds read in OpENer before February 10, 2021 allows remote attackers to read stack data via crafted EtherNet/IP packets. The CPF parser processes three items at the end of its 512-byte receive buffer without checking remaining bytes, then copies adjacent stack values into a socket-address response item. No authentication or user interaction is required, and the documented impact is limited to confidentiality.

CVSS severity7.5
High
EPSS probability1.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in OpENer before February 10, 2021 allows remote attackers to read stack data via crafted EtherNet/IP packets. The CPF parser processes three items at the end of its 512-byte receive buffer without checking remaining bytes, then copies adjacent stack values into a socket-address response item. No authentication or user interaction is required, and the documented impact is limited to confidentiality.

The record

CVE
CVE-2021-27482
Published
May 12, 2022
Updated
Apr 16, 2025
Vendor
EIPStackGroup
Product
OpENer
Classifications
CWE-125, T0866
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 12, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <Feb 10, 2021

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

EIPStackGroup · OpENerversion=unspecified <Feb 10, 2021

Published CVSS scores

5.0NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5ICS-CERTCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T0866Exploitation of Remote Services

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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