# CVE-2021-28362: Integer overflow in n/a

> An integer underflow in Contiki OS allows remote attackers to cause a denial of service via crafted IPv6 packets with invalid extension headers.

- **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:** 24 Mar 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-pcjq-cmp7-76vx

## What is CVE-2021-28362?

CVE-2021-28362 is a high-severity vulnerability in n/a, published on 24 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Contiki through 3.0. When sending an ICMPv6 error message because of invalid extension header options in an incoming IPv6 packet, there is an attempt to remove the RPL extension headers. Because the packet length and the extension header length are unchecked (with respect to the available data) at this stage, and these variables are susceptible to integer underflow, it is possible to construct an invalid extension header that will cause memory corruption issues and lead to a Denial-of-Service condition. This is related to rpl-ext-header.c.

Weakness: CWE-191 (Integer Underflow (Wrap or Wraparound))

## Which versions are affected by CVE-2021-28362?

It affects 1 product.


Products: Contiki-Os Contiki.

## How do I fix CVE-2021-28362?

No fix has been published for CVE-2021-28362 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-28362 being exploited?

There is no known exploitation of CVE-2021-28362 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-40523](https://insights.sbomify.com/CVE-2021-40523/): Denial of service in n/a (high 7.5)
- [CVE-2021-38386](https://insights.sbomify.com/CVE-2021-38386/): Memory corruption in n/a (high 7.5)
- [CVE-2021-38387](https://insights.sbomify.com/CVE-2021-38387/): Denial of service in n/a (high 7.5)
- [CVE-2021-38311](https://insights.sbomify.com/CVE-2021-38311/): Denial of service in n/a (high 7.5)
- [CVE-2020-13984](https://insights.sbomify.com/CVE-2020-13984/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28362 and fix it if it is affected.

What it is: CVE-2021-28362 is a high-severity vulnerability in n/a, published on 24 Mar 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-2021-28362 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-2021-28362/ (Markdown: https://insights.sbomify.com/CVE-2021-28362/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28362
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28362
- OSV: https://osv.dev/vulnerability/CVE-2021-28362

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28362/
Summaries are generated and may contain mistakes; the official description above is the record.