# CVE-2023-4520: Cross-site scripting in FV Flowplayer Video Player

> Unauthenticated attackers can inject scripts and modify user metadata in the FV Flowplayer Video Player WordPress plugin.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/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:** Not needed
- **Fix available:** No
- **Published:** 25 Aug 2023
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-v3w9-6427-5g27

## What is CVE-2023-4520?

CVE-2023-4520 is a medium-severity cross-site scripting vulnerability in foliovision FV Flowplayer Video Player, published on 25 Aug 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The FV Flowplayer Video Player plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘_fv_player_user_video’ parameter saved via the 'save' function hooked via init, and the plugin is also vulnerable to Arbitrary Usermeta Update via the 'save' function in versions up to, and including, 7.5.37.7212 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page, and makes it possible to update the user metas arbitrarily, but the meta value can only be a string.

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

## Which versions are affected by CVE-2023-4520?

It affects 1 product.


Products: Foliovision Fv Flowplayer Video Player.

## How do I fix CVE-2023-4520?

No fix has been published for CVE-2023-4520 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-4520 being exploited?

There is no known exploitation of CVE-2023-4520 in the wild and no public exploit code.

## Other vulnerabilities in foliovision FV Flowplayer Video Player

- [CVE-2019-14801](https://insights.sbomify.com/CVE-2019-14801/): SQL injection in n/a (critical 9.8)
- [CVE-2019-13573](https://insights.sbomify.com/CVE-2019-13573/): SQL injection in n/a (critical 9.8)
- [CVE-2024-6338](https://insights.sbomify.com/CVE-2024-6338/): FV Player <= 7.5.46.7212 - Authenticated (Subscriber+) SQL Injection via exclude Parameter (high 8.8)
- [CVE-2023-30499](https://insights.sbomify.com/CVE-2023-30499/): WordPress FV Flowplayer Video Player Plugin <= 7.5.32.7212 is vulnerable to Cross Site Scripting (XSS) (high 7.1)
- [CVE-2022-25607](https://insights.sbomify.com/CVE-2022-25607/): WordPress FV Flowplayer Video Player plugin <= 7.5.15.727 - SQL Injection (SQLi) vulnerability (medium 6.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-4520 and fix it if it is affected.

What it is: CVE-2023-4520 is a medium-severity cross-site scripting vulnerability in foliovision FV Flowplayer Video Player, published on 25 Aug 2023. 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-2023-4520 in the wild and no public exploit code.

Affected product: foliovision FV Flowplayer Video Player. 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-2023-4520/ (Markdown: https://insights.sbomify.com/CVE-2023-4520/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-4520
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-4520
- OSV: https://osv.dev/vulnerability/CVE-2023-4520

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-4520/
Summaries are generated and may contain mistakes; the official description above is the record.