# CVE-2020-10136: IP-in-IP protocol allows a remote, unauthenticated attacker to route arbitrary network traffic

> Remote attackers can bypass access controls and route arbitrary traffic by exploiting IP-in-IP encapsulation flaws, affecting systems with this protocol enabled.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Jun 2020
- **Updated:** 3 Nov 2025
- **Also known as:** GHSA-8gxc-83hw-9578

## What is CVE-2020-10136?

CVE-2020-10136 is a medium-severity vulnerability in Cisco Nx-Os, published on 2 Jun 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

IP-in-IP protocol specifies IP Encapsulation within IP standard (RFC 2003, STD 1) that decapsulate and route IP-in-IP traffic is vulnerable to spoofing, access-control bypass and other unexpected behavior due to the lack of validation to verify network packets before decapsulation and routing.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2020-10136?

It affects 6 products.


Products: Cisco Nx-Os, Cisco Ucs Manager, Cisco Unified Computing System, Digi Saros, Hp X3220nr Firmware, Treck Tcp\/Ip.

## How do I fix CVE-2020-10136?

No fix has been published for CVE-2020-10136 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-10136 being exploited?

There is no known exploitation of CVE-2020-10136 in the wild and no public exploit code.

Public exploit code:

- Scanner and attack suite for hosts that forward unauthenticated packets via IPIP and GRE protocols. (CVE-2020-10136 CVE-2024-7595) (github_poc): https://github.com/PapayaJackal/ipeeyoupeewepee

## Other vulnerabilities in Cisco Nx-Os

- [CVE-2024-20399](https://insights.sbomify.com/CVE-2024-20399/): Cisco NX-OS Command Injection (medium 6.0, exploited in the wild)
- [CVE-2021-1361](https://insights.sbomify.com/CVE-2021-1361/): Cisco NX-OS Software Unauthenticated Arbitrary File Actions Vulnerability (critical 9.8)
- [CVE-2018-0301](https://insights.sbomify.com/CVE-2018-0301/): Memory corruption in Cisco NX-OS unknown (critical 9.8)
- [CVE-2016-1453](https://insights.sbomify.com/CVE-2016-1453/): Memory corruption in n/a (critical 9.8)
- [CVE-2016-1341](https://insights.sbomify.com/CVE-2016-1341/): Hardcoded credentials in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-10136 and fix it if it is affected.

What it is: CVE-2020-10136 is a medium-severity vulnerability in Cisco Nx-Os, published on 2 Jun 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-2020-10136 in the wild and no public exploit code.

Affected product: Cisco Nx-Os. 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-2020-10136/ (Markdown: https://insights.sbomify.com/CVE-2020-10136/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-10136
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-10136
- OSV: https://osv.dev/vulnerability/CVE-2020-10136

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-10136/
Summaries are generated and may contain mistakes; the official description above is the record.