# CVE-2020-17469: Null dereference in n/a

> An uninitialized pointer dereference in FNET's IPv6 fragment reassembly allows remote attackers to cause a Denial of Service.

- **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:** 11 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-ggpj-5v2h-5jrp

## What is CVE-2020-17469?

CVE-2020-17469 is a high-severity vulnerability in n/a, 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 issue was discovered in FNET through 4.6.4. The code for IPv6 fragment reassembly tries to access a previous fragment starting from a network incoming fragment that still doesn't have a reference to the previous one (which supposedly resides in the reassembly list). When faced with an incoming fragment that belongs to a non-empty fragment list, IPv6 reassembly must check that there are no empty holes between the fragments: this leads to an uninitialized pointer dereference in _fnet_ip6_reassembly in fnet_ip6.c, and causes Denial-of-Service.

Weakness: CWE-824 (Access of Uninitialized Pointer)

## Which versions are affected by CVE-2020-17469?

It affects 1 product.


Products: Butok Fnet.

## How do I fix CVE-2020-17469?

No fix has been published for CVE-2020-17469 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-17469 being exploited?

There is no known exploitation of CVE-2020-17469 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-27633](https://insights.sbomify.com/CVE-2020-27633/): Weak cryptography in n/a (critical 9.1)
- [CVE-2020-17467](https://insights.sbomify.com/CVE-2020-17467/): Information disclosure in n/a (critical 9.1)
- [CVE-2020-24383](https://insights.sbomify.com/CVE-2020-24383/): Information disclosure in n/a (critical 9.1)
- [CVE-2020-17468](https://insights.sbomify.com/CVE-2020-17468/): Denial of service in n/a (high 7.5)
- [CVE-2020-17470](https://insights.sbomify.com/CVE-2020-17470/): Weak cryptography in n/a (medium 5.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-17469 and fix it if it is affected.

What it is: CVE-2020-17469 is a high-severity vulnerability in n/a, 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-2020-17469 in the wild and no public exploit code.

Affected product: n/a. 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-2020-17469/ (Markdown: https://insights.sbomify.com/CVE-2020-17469/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-17469
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-17469
- OSV: https://osv.dev/vulnerability/CVE-2020-17469

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-17469/
Summaries are generated and may contain mistakes; the official description above is the record.