# CVE-2020-27295: Denial of service in OPC UA Tunneller

> An attacker can cause a denial-of-service condition in the OPC UA Tunneller through uncontrolled resource consumption.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 26 Jan 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-gc6c-6m8m-8g6g

## What is CVE-2020-27295?

CVE-2020-27295 is a high-severity denial of service vulnerability in OPC UA Tunneller, published on 26 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The affected product has uncontrolled resource consumption issues, which may allow an attacker to cause a denial-of-service condition on the OPC UA Tunneller (versions prior to 6.3.0.8233).

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-27295?

It affects 1 product.


Products: Honeywell Opc Ua Tunneller.

## How do I fix CVE-2020-27295?

No fix has been published for CVE-2020-27295 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-27295 being exploited?

There is no known exploitation of CVE-2020-27295 in the wild and no public exploit code.

## Other vulnerabilities in OPC UA Tunneller

- [CVE-2020-27297](https://insights.sbomify.com/CVE-2020-27297/): Memory corruption in OPC UA Tunneller (critical 9.8)
- [CVE-2020-27299](https://insights.sbomify.com/CVE-2020-27299/): Information disclosure in OPC UA Tunneller (critical 9.1)
- [CVE-2020-27274](https://insights.sbomify.com/CVE-2020-27274/): Denial of service in OPC UA Tunneller (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27295 and fix it if it is affected.

What it is: CVE-2020-27295 is a high-severity denial of service vulnerability in OPC UA Tunneller, published on 26 Jan 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-2020-27295 in the wild and no public exploit code.

Affected product: OPC UA Tunneller. 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-2020-27295/ (Markdown: https://insights.sbomify.com/CVE-2020-27295/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27295
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27295
- OSV: https://osv.dev/vulnerability/CVE-2020-27295

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27295/
Summaries are generated and may contain mistakes; the official description above is the record.