# CVE-2020-3363: Cisco Small Business Smart and Managed Switches Denial of Service Vulnerability

> An unauthenticated remote attacker can cause a denial of service on Cisco Small Business switches by sending crafted IPv6 packets, triggering an unexpected reboot.

- **Severity:** High 8.6 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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:** 17 Aug 2020
- **Updated:** 13 Nov 2024
- **Also known as:** GHSA-2hxc-5mh2-9rxg

## What is CVE-2020-3363?

CVE-2020-3363 is a high-severity denial of service vulnerability in Cisco Small Business 250 Series Smart Switches Software, published on 17 Aug 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the IPv6 packet processing engine of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient validation of incoming IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet through an affected device. A successful exploit could allow the attacker to cause an unexpected reboot of the switch, leading to a DoS condition. This vulnerability is specific to IPv6 traffic. IPv4 traffic is not affected.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-3363?

It affects 114 products.


Products: Cisco Sf200-24 Firmware, Cisco Sf200-24fp Firmware, Cisco Sf200-24p Firmware, Cisco Sf200-48 Firmware, Cisco Sf200-48p Firmware, Cisco Sf250-24 Firmware, Cisco Sf250-24p Firmware, Cisco Sf250-48 Firmware, Cisco Sf250-48hp Firmware, Cisco Sf300-08 Firmware, Cisco Sf300-24 Firmware, Cisco Sf300-24mp Firmware, Cisco Sf300-24p Firmware, Cisco Sf300-24pp Firmware, Cisco Sf300-48 Firmware, Cisco Sf300-48p Firmware, Cisco Sf300-48pp Firmware, Cisco Sf302-08 Firmware, Cisco Sf302-08mp Firmware, Cisco Sf302-08mpp Firmware and 94 more.

## How do I fix CVE-2020-3363?

No fix has been published for CVE-2020-3363 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3363 being exploited?

There is no known exploitation of CVE-2020-3363 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Small Business 250 Series Smart Switches Software

- [CVE-2018-15439](https://insights.sbomify.com/CVE-2018-15439/): Cisco Small Business Switches Privileged Access Vulnerability (critical 9.8)
- [CVE-2020-3297](https://insights.sbomify.com/CVE-2020-3297/): Cisco Small Business Smart and Managed Switches Session Management Vulnerability (high 8.1)
- [CVE-2019-12636](https://insights.sbomify.com/CVE-2019-12636/): Cisco Small Business Smart and Managed Switches Cross-Site Request Forgery Vulnerability (high 8.1)
- [CVE-2019-15993](https://insights.sbomify.com/CVE-2019-15993/): Cisco Small Business Switches Information Disclosure Vulnerability (high 7.5)
- [CVE-2019-1859](https://insights.sbomify.com/CVE-2019-1859/): Cisco Small Business Switches Secure Shell Certificate Authentication Bypass Vulnerability (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3363 and fix it if it is affected.

What it is: CVE-2020-3363 is a high-severity denial of service vulnerability in Cisco Small Business 250 Series Smart Switches Software, published on 17 Aug 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-2020-3363 in the wild and no public exploit code.

Affected product: Cisco Small Business 250 Series Smart Switches Software. 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-2020-3363/ (Markdown: https://insights.sbomify.com/CVE-2020-3363/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3363
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3363
- OSV: https://osv.dev/vulnerability/CVE-2020-3363

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3363/
Summaries are generated and may contain mistakes; the official description above is the record.