# CVE-2020-3121: Cisco Small Business Smart and Managed Switches Cross-Site Scripting Vulnerability

> An unauthenticated remote attacker can execute arbitrary script code or access sensitive browser-based information by tricking a user into clicking a malicious link.

- **Severity:** Medium 6.1 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 26 Jan 2020
- **Updated:** 15 Nov 2024
- **Also known as:** GHSA-p382-hh5c-h4rq

## What is CVE-2020-3121?

CVE-2020-3121 is a medium-severity cross-site scripting vulnerability in Cisco 550X Series Stackable Managed Switches, published on 26 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A vulnerability in the web-based management interface of Cisco Small Business Smart and Managed Switches could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of the affected device. An attacker could exploit this vulnerability by persuading a user of the interface to click a malicious link and access a specific page. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2020-3121?

It affects 45 products.


Products: Cisco Sf350-48 Firmware, Cisco Sf350-48mp Firmware, Cisco Sf350-48p Firmware, Cisco Sf550x-24 Firmware, Cisco Sf550x-24p Firmware, Cisco Sf550x-48 Firmware, Cisco Sf550x-48mp Firmware, Cisco Sf550x-48p Firmware, Cisco Sg250-08 Firmware, Cisco Sg250-08hp Firmware, Cisco Sg250-10p Firmware, Cisco Sg250-18 Firmware, Cisco Sg250-24 Firmware, Cisco Sg250-24p Firmware, Cisco Sg250-26 Firmware, Cisco Sg250-26hp Firmware, Cisco Sg250-26p Firmware, Cisco Sg250-48 Firmware, Cisco Sg250-48hp Firmware, Cisco Sg250-50 Firmware and 25 more.

## How do I fix CVE-2020-3121?

No fix has been published for CVE-2020-3121 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-3121 being exploited?

There is no known exploitation of CVE-2020-3121 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-3121 and fix it if it is affected.

What it is: CVE-2020-3121 is a medium-severity cross-site scripting vulnerability in Cisco 550X Series Stackable Managed Switches, published on 26 Jan 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-3121 in the wild and no public exploit code.

Affected product: Cisco 550X Series Stackable Managed Switches. 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-2020-3121/ (Markdown: https://insights.sbomify.com/CVE-2020-3121/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-3121
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-3121
- OSV: https://osv.dev/vulnerability/CVE-2020-3121

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-3121/
Summaries are generated and may contain mistakes; the official description above is the record.