# CVE-2021-24574: Simple Banner < 2.10.4 - Authenticated Stored XSS

> Authenticated administrators can inject malicious scripts via unsanitized settings in the Simple Banner WordPress plugin, leading to stored XSS.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 23 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-jx5c-5jv3-g74m

## What is CVE-2021-24574?

CVE-2021-24574 is a medium-severity cross-site scripting vulnerability in Unknown Simple Banner, published on 23 Aug 2021. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

The Simple Banner WordPress plugin before 2.10.4 does not sanitise and escape one of its settings, allowing high privilege users such as admin to use Cross-Site Scripting payload even when the unfiltered_html capability is disallowed.

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

## Which versions are affected by CVE-2021-24574?

It affects 1 product.


Products: Simple Banner Project Simple Banner.

## How do I fix CVE-2021-24574?

No fix has been published for CVE-2021-24574 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24574 being exploited?

There is no known exploitation of CVE-2021-24574 in the wild and no public exploit code.

## Other vulnerabilities in Unknown Simple Banner

- [CVE-2022-2515](https://insights.sbomify.com/CVE-2022-2515/): Simple Banner <= 2.11.0 - Authenticated Stored Cross-Site Scripting (medium 6.4)
- [CVE-2022-0446](https://insights.sbomify.com/CVE-2022-0446/): Simple Banner < 2.12.0 - Admin+ Stored Cross Site Scripting (medium 4.8)
- [CVE-2024-12769](https://insights.sbomify.com/CVE-2024-12769/): Simple Banner < 3.0.4 - Admin+ Stored XSS (low 3.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24574 and fix it if it is affected.

What it is: CVE-2021-24574 is a medium-severity cross-site scripting vulnerability in Unknown Simple Banner, published on 23 Aug 2021. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-24574 in the wild and no public exploit code.

Affected product: Unknown Simple Banner. 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-2021-24574/ (Markdown: https://insights.sbomify.com/CVE-2021-24574/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24574
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24574
- OSV: https://osv.dev/vulnerability/CVE-2021-24574

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24574/
Summaries are generated and may contain mistakes; the official description above is the record.