# CVE-2021-1437: Cisco Aironet Access Points FlexConnect Upgrade Information Disclosure Vulnerability

> Unauthenticated remote attackers can download arbitrary files from Cisco Aironet Access Points due to unrestricted TFTP configuration in FlexConnect Upgrade.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **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:** 8 Nov 2024
- **Also known as:** GHSA-777j-pmq7-4px5

## What is CVE-2021-1437?

CVE-2021-1437 is a high-severity vulnerability in Cisco Wireless Lan Controller Software, published on 24 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the FlexConnect Upgrade feature of Cisco Aironet Series Access Points Software could allow an unauthenticated, remote attacker to obtain confidential information from an affected device. This vulnerability is due to an unrestricted Trivial File Transfer Protocol (TFTP) configuration. An attacker could exploit this vulnerability by sending a specific TFTP request to an affected device. A successful exploit could allow the attacker to download any file from the filesystem of the affected access point (AP).

Weakness: CWE-275

## Which versions are affected by CVE-2021-1437?

It affects 3 products.


Products: Cisco Aironet Access Point Software, Cisco Catalyst 9800 Firmware, Cisco Wireless Lan Controller Software.

## How do I fix CVE-2021-1437?

No fix has been published for CVE-2021-1437 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1437 being exploited?

There is no known exploitation of CVE-2021-1437 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Wireless Lan Controller Software

- [CVE-2017-3831](https://insights.sbomify.com/CVE-2017-3831/): Auth bypass in Cisco Mobility Express 1800 Access Point Series (critical 9.8)
- [CVE-2022-20622](https://insights.sbomify.com/CVE-2022-20622/): Cisco Embedded Wireless Controller with Catalyst Access Points IP Flood Denial of Service Vulnerability (high 8.6)
- [CVE-2018-0234](https://insights.sbomify.com/CVE-2018-0234/): Denial of service in Cisco Aironet 1810, 1830, and 1850 Series Access Points (high 8.6)
- [CVE-2016-1419](https://insights.sbomify.com/CVE-2016-1419/): Denial of service in n/a (high 8.1)
- [CVE-2016-6362](https://insights.sbomify.com/CVE-2016-6362/): Privilege escalation in n/a (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1437 and fix it if it is affected.

What it is: CVE-2021-1437 is a high-severity vulnerability in Cisco Wireless Lan Controller Software, 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-2021-1437 in the wild and no public exploit code.

Affected product: Cisco Wireless Lan Controller 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-2021-1437/ (Markdown: https://insights.sbomify.com/CVE-2021-1437/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1437
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1437
- OSV: https://osv.dev/vulnerability/CVE-2021-1437

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-1437/
Summaries are generated and may contain mistakes; the official description above is the record.