# CVE-2020-13556: Memory corruption in EIP Stack Group

> Remote attackers can execute arbitrary code via crafted network requests exploiting an out-of-bounds write in the OpENer Ethernet/IP server.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-vp7f-g57q-p9jx

## What is CVE-2020-13556?

CVE-2020-13556 is a critical memory corruption vulnerability in EIP Stack Group, published on 11 Dec 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2020-13556?

It affects 1 product.


Products: Opener Project Opener.

## How do I fix CVE-2020-13556?

No fix has been published for CVE-2020-13556 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-13556 being exploited?

There is no known exploitation of CVE-2020-13556 in the wild and no public exploit code.

## Other vulnerabilities in EIP Stack Group

- [CVE-2022-43604](https://insights.sbomify.com/CVE-2022-43604/): Memory corruption in OpENer (critical 10.0)
- [CVE-2022-43605](https://insights.sbomify.com/CVE-2022-43605/): Memory corruption in OpENer (critical 10.0)
- [CVE-2026-51540](https://insights.sbomify.com/CVE-2026-51540/): Integer overflow in n/a (critical 9.8)
- [CVE-2026-51536](https://insights.sbomify.com/CVE-2026-51536/): Integer overflow in n/a (critical 9.1)
- [CVE-2026-51537](https://insights.sbomify.com/CVE-2026-51537/): Memory corruption in n/a (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-13556 and fix it if it is affected.

What it is: CVE-2020-13556 is a critical memory corruption vulnerability in EIP Stack Group, published on 11 Dec 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-13556 in the wild and no public exploit code.

Affected product: EIP Stack Group. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-13556/ (Markdown: https://insights.sbomify.com/CVE-2020-13556/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-13556
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-13556
- OSV: https://osv.dev/vulnerability/CVE-2020-13556

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-13556/
Summaries are generated and may contain mistakes; the official description above is the record.