# CVE-2021-40142: Memory corruption in n/a

> Remote attackers can cause a denial of service in OPC Foundation Local Discovery Server by sending crafted messages that trigger a buffer over-read.

- **Severity:** High 7.5 (`CVSS:3.1/AC:L/AV:N/A:H/C:N/I:N/PR:N/S:U/UI:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Aug 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-5524-cf37-2p8f

## What is CVE-2021-40142?

CVE-2021-40142 is a high-severity memory corruption vulnerability in Siemens Telecontrol Server Basic, published on 27 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In OPC Foundation Local Discovery Server (LDS) before 1.04.402.463, remote attackers can cause a denial of service (DoS) by sending carefully crafted messages that lead to Access of a Memory Location After the End of a Buffer.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2021-40142?

It affects 7 products.


Products: Opcfoundation Local Discover Server, Siemens Simatic Net Pc, Siemens Simatic Process Historian Opc Ua Server Firmware, Siemens Simatic Wincc, Siemens Simatic Wincc Runtime, Siemens Simatic Wincc Unified Scada Runtime, Siemens Telecontrol Server Basic.

## How do I fix CVE-2021-40142?

No fix has been published for CVE-2021-40142 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-40142 being exploited?

There is no known exploitation of CVE-2021-40142 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-40142 and fix it if it is affected.

What it is: CVE-2021-40142 is a high-severity memory corruption vulnerability in Siemens Telecontrol Server Basic, published on 27 Aug 2021. 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-2021-40142 in the wild and no public exploit code.

Affected product: Siemens Telecontrol Server Basic. 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-2021-40142/ (Markdown: https://insights.sbomify.com/CVE-2021-40142/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40142
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-40142
- OSV: https://osv.dev/vulnerability/CVE-2021-40142

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-40142/
Summaries are generated and may contain mistakes; the official description above is the record.