# CVE-2020-3559: Cisco Aironet Access Point Authentication Flood Denial of Service Vulnerability

> An unauthenticated remote attacker can cause a Cisco Aironet Access Point to reload by sending excessive authentication requests.

- **Severity:** Medium 6.8 (`CVSS:3.0/AV:N/AC:H/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:** 24 Sep 2020
- **Updated:** 13 Nov 2024
- **Also known as:** GHSA-mmvp-2hg2-g76c

## What is CVE-2020-3559?

CVE-2020-3559 is a medium-severity denial of service vulnerability in Cisco Aironet Access Point Software, published on 24 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in Cisco Aironet Access Point (AP) Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to improper handling of clients that are trying to connect to the AP. An attacker could exploit this vulnerability by sending authentication requests from multiple clients to an affected device. A successful exploit could allow the attacker to cause the affected device to reload.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-3559?

It affects 4 products.


Products: Cisco Access Points, Cisco Aironet Access Point Software, Cisco Business Access Points, Cisco Wireless Lan Controller.

## How do I fix CVE-2020-3559?

No fix has been published for CVE-2020-3559 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3559 being exploited?

There is no known exploitation of CVE-2020-3559 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Aironet Access Point Software

- [CVE-2020-3560](https://insights.sbomify.com/CVE-2020-3560/): Cisco Aironet Access Points UDP Flooding Denial of Service Vulnerability (high 8.6)
- [CVE-2020-3552](https://insights.sbomify.com/CVE-2020-3552/): Cisco Aironet Access Points Ethernet Wired Clients Denial of Service Vulnerability (high 7.4)
- [CVE-2019-1920](https://insights.sbomify.com/CVE-2019-1920/): Cisco IOS Access Points Software 802.11r Fast Transition Denial of Service Vulnerability (high 7.4)
- [CVE-2018-0441](https://insights.sbomify.com/CVE-2018-0441/): Cisco IOS Access Points Software 802.11r Fast Transition Denial of Service Vulnerability (high 7.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3559 and fix it if it is affected.

What it is: CVE-2020-3559 is a medium-severity denial of service vulnerability in Cisco Aironet Access Point Software, published on 24 Sep 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-2020-3559 in the wild and no public exploit code.

Affected product: Cisco Aironet Access Point 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-2020-3559/ (Markdown: https://insights.sbomify.com/CVE-2020-3559/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3559
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3559
- OSV: https://osv.dev/vulnerability/CVE-2020-3559

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3559/
Summaries are generated and may contain mistakes; the official description above is the record.