# CVE-2020-25705: Information disclosure in Siemens Lunux Based Products

> An attacker can bypass UDP source port randomization to scan open ports, exposing network topology information on affected Linux-based systems.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** A-174737972, ASB-A-174737972, DEBIAN-CVE-2020-25705, GHSA-33cf-w34p-g6pj, UBUNTU-CVE-2020-25705

## What is CVE-2020-25705?

CVE-2020-25705 is a high-severity vulnerability in Linux kernel, published on 17 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A flaw in ICMP packets in the Linux kernel may allow an attacker to quickly scan open UDP ports. This flaw allows an off-path remote attacker to effectively bypass source port UDP randomization. Software that relies on UDP source port randomization are indirectly affected as well on the Linux Based Products (RUGGEDCOM RM1224: All versions between v5.0 and v6.4, SCALANCE M-800: All versions between v5.0 and v6.4, SCALANCE S615: All versions between v5.0 and v6.4, SCALANCE SC-600: All versions prior to v2.1.3, SCALANCE W1750D: v8.3.0.1, v8.6.0, and v8.7.0, SIMATIC Cloud Connect 7: All versions, SIMATIC MV500 Family: All versions, SIMATIC NET CP 1243-1 (incl. SIPLUS variants): Versions 3.1.39 and later, SIMATIC NET CP 1243-7 LTE EU: Version

Weakness: CWE-330 (Use of Insufficiently Random Values)

## Which versions are affected by CVE-2020-25705?

It affects 2 products.


Products: Linux kernel, Redhat Enterprise Linux.

## How do I fix CVE-2020-25705?

Apply the vendor's patch.

## Is CVE-2020-25705 being exploited?

There is no known exploitation of CVE-2020-25705 in the wild and no public exploit code.

Public exploit code:

- PoC for CVE-2020-25705 POC-2020-25705 (github_poc): https://github.com/tdwyer/CVE-2020-25705
- https://github.com/nanopathi/linux-4.19.72_CVE-2020-25705 (github_poc): https://github.com/nanopathi/linux-4.19.72_CVE-2020-25705

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-25705 and fix it if it is affected.

What it is: CVE-2020-25705 is a high-severity vulnerability in Linux kernel, published on 17 Nov 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-2020-25705 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2020-25705/ (Markdown: https://insights.sbomify.com/CVE-2020-25705/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-25705
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-25705
- OSV: https://osv.dev/vulnerability/CVE-2020-25705

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-25705/
Summaries are generated and may contain mistakes; the official description above is the record.