# CVE-2021-24528: FluentSMTP < 2.0.1 - Authenticated Stored XSS

> Authenticated attackers with plugin management roles can inject malicious scripts via unsanitized SMTP settings, leading to stored XSS.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/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:** 30 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-vcw9-mv32-wmgq

## What is CVE-2021-24528?

CVE-2021-24528 is a medium-severity cross-site scripting vulnerability in Unknown FluentSMTP – WordPress Mail SMTP, SES, SendGrid, Mailgun and Any SMTP Plugin, published on 30 Aug 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

The FluentSMTP WordPress plugin before 2.0.1 does not sanitize parameters before storing the settings in the database, nor does the plugin escape the values before outputting them when viewing the SMTP settings set by this plugin, leading to a stored cross site scripting (XSS) vulnerability. Only users with roles capable of managing plugins can modify the plugin's settings.

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

## Which versions are affected by CVE-2021-24528?

It affects 1 product.


Products: Wpmanageninja Fluentsmtp.

## How do I fix CVE-2021-24528?

No fix has been published for CVE-2021-24528 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24528 being exploited?

There is no known exploitation of CVE-2021-24528 in the wild and no public exploit code.

## Other vulnerabilities in Unknown FluentSMTP – WordPress Mail SMTP, SES, SendGrid, Mailgun and Any SMTP Plugin

- [CVE-2023-3087](https://insights.sbomify.com/CVE-2023-3087/): FluentSMTP <= 2.2.4 - Unauthenticated Stored Cross-Site Scripting via Email Subject (high 7.2)
- [CVE-2023-0219](https://insights.sbomify.com/CVE-2023-0219/): FluentSMTP < 2.2.3 - Stored XSS via Email Logs (medium 5.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24528 and fix it if it is affected.

What it is: CVE-2021-24528 is a medium-severity cross-site scripting vulnerability in Unknown FluentSMTP – WordPress Mail SMTP, SES, SendGrid, Mailgun and Any SMTP Plugin, published on 30 Aug 2021. 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-2021-24528 in the wild and no public exploit code.

Affected product: Unknown FluentSMTP – WordPress Mail SMTP, SES, SendGrid, Mailgun and Any SMTP Plugin. 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-2021-24528/ (Markdown: https://insights.sbomify.com/CVE-2021-24528/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24528
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24528
- OSV: https://osv.dev/vulnerability/CVE-2021-24528

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24528/
Summaries are generated and may contain mistakes; the official description above is the record.