# CVE-2021-4252: WP-Ban ban-options.php toggle_checkbox cross site scripting

> A cross-site scripting vulnerability in the WP-Ban WordPress plugin allows remote attackers to inject malicious scripts via the User-Agent header.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 18 Dec 2022
- **Updated:** 15 Apr 2025
- **Also known as:** GHSA-q9f9-65vf-f4jf

## What is CVE-2021-4252?

CVE-2021-4252 is a low-severity cross-site scripting vulnerability in unspecified WP-Ban, published on 18 Dec 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A vulnerability, which was classified as problematic, has been found in WP-Ban. This issue affects the function toggle_checkbox of the file ban-options.php. The manipulation of the argument $_SERVER["HTTP_USER_AGENT"] leads to cross site scripting. The attack may be initiated remotely. The name of the patch is 13e0b1e922f3aaa3f8fcb1dd6d50200dd693fd76. It is recommended to apply a patch to fix this issue. The identifier VDB-216209 was assigned to this vulnerability.

Weakness: CWE-707 (Improper Neutralization)

## Which versions are affected by CVE-2021-4252?

It affects 1 product.


Products: Wp-Ban Project Wp-Ban.

## How do I fix CVE-2021-4252?

No fix has been published for CVE-2021-4252 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4252 being exploited?

There is no known exploitation of CVE-2021-4252 in the wild and no public exploit code.

## Other vulnerabilities in unspecified WP-Ban

- [CVE-2022-4260](https://insights.sbomify.com/CVE-2022-4260/): WP-Ban < 1.69.1 - Admin+ Stored XSS (medium 4.8)
- [CVE-2014-6230](https://insights.sbomify.com/CVE-2014-6230/): Security feature bypass in n/a (medium 4.3)
- [CVE-2022-4631](https://insights.sbomify.com/CVE-2022-4631/): WP-Ban ban-options.php cross site scripting (low 3.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4252 and fix it if it is affected.

What it is: CVE-2021-4252 is a low-severity cross-site scripting vulnerability in unspecified WP-Ban, published on 18 Dec 2022. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-4252 in the wild and no public exploit code.

Affected product: unspecified WP-Ban. 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-2021-4252/ (Markdown: https://insights.sbomify.com/CVE-2021-4252/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4252
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4252
- OSV: https://osv.dev/vulnerability/CVE-2021-4252

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-4252/
Summaries are generated and may contain mistakes; the official description above is the record.