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Vulnerability record · CVE-2020-13556 · published 11 December 2020

CVE-2020-13556: Opener project opener out-of-bounds write vulnerability

Opener Project · Opener

An out-of-bounds write vulnerability exists in the Ethernet/IP server functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. A specially crafted series of network requests can lead to remote code execution. An attacker can send a sequence of requests to trigger this vulnerability.

9.8 CVSS 3.1 Critical EPSS 4.7% · top 8.5% CWE-787 · Out-of-bounds write
9.8CVSS 3.1 base score, v2 7.5
4.7%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

An out-of-bounds write vulnerability exists in the Ethernet/IP server functionality of EIP Stack Group OpENer 2.3 and development commit 8c73bf3. A specially crafted series of network requests can lead to remote code execution. An attacker can send a sequence of requests to trigger this vulnerability.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://talosintelligence.com/vulnerability_reports/TALOS-2020-1170 ExploitTechnical DescriptionThird Party Advisory
https://talosintelligence.com/vulnerability_reports/TALOS-2020-1170 ExploitTechnical DescriptionThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2021-21777Opener project opener out-of-bounds read vulnerabilityAn information disclosure vulnerability exists in the Ethernet/IP UDP handler functionality of EIP Stack Group OpENer 2.3 and development commit 8c73…EPSS 1.7%9.8CVE-2026-51540Opener project opener vulnerabilityOpENer 2.3.0 (master branch up to commit 76b95cf) is vulnerable to a severe memory corruption issue caused by an integer underflow in the processing …EPSS 0.57%9.8CVE-2022-43604Opener project opener out-of-bounds write vulnerabilityAn out-of-bounds write vulnerability exists in the GetAttributeList attribute_count_request functionality of EIP Stack Group OpENer development commi…EPSS 14%9.8CVE-2022-43605Opener project opener out-of-bounds write vulnerabilityAn out-of-bounds write vulnerability exists in the SetAttributeList attribute_count_request functionality of EIP Stack Group OpENer development commi…EPSS 14%9.1CVE-2026-51536Opener project opener integer overflow vulnerabilityIn OpENer 2.3.0 (commit 76b95cf) when parsing incoming CIP (Common Industrial Protocol) network packets, the length parameter is inconsistently typed…EPSS 0.63%9.1CVE-2026-51537Opener project opener out-of-bounds read vulnerabilityEIPStackGroup OpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in Connection Manager handling of ForwardOpen requests when processing sh…EPSS 0.65%9.1CVE-2026-51538Opener project opener improper access control vulnerabilityEIPStackGroup OpENer 2.3.0 (commit 76b95cf) suffers from an Incorrect Access Control vulnerability in its handling of encapsulation sessions. When th…EPSS 0.52%9.1CVE-2026-51541Opener project opener out-of-bounds read vulnerabilityOpENer 2.3.0 (commit 76b95cf) has an out-of-bounds read issue in CIP message parsing when handling malformed explicit requests with a forged EPath si…EPSS 0.55%

Source: NIST National Vulnerability Database (record CVE-2020-13556), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.