# CVE-2021-4422: POST SMTP Mailer <= 2.0.20 - Cross-Site Request Forgery Bypass

> Unauthenticated attackers can trick administrators into triggering CSV exports via forged requests, potentially exposing email logs.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/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:** 12 Jul 2023
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-7qhm-w96c-j5vq

## What is CVE-2021-4422?

CVE-2021-4422 is a medium-severity vulnerability in saadiqbal Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App, published on 12 Jul 2023. 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

The POST SMTP Mailer plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 2.0.20. This is due to missing or incorrect nonce validation on the handleCsvExport() function. This makes it possible for unauthenticated attackers to trigger a CSV export via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2021-4422?

It affects 1 product.


Products: Wpexperts Post Smtp.

## How do I fix CVE-2021-4422?

No fix has been published for CVE-2021-4422 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4422 being exploited?

There is no known exploitation of CVE-2021-4422 in the wild and no public exploit code.

## Other vulnerabilities in saadiqbal Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App

- [CVE-2023-6875](https://insights.sbomify.com/CVE-2023-6875/): Auth bypass in Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App (critical 9.8)
- [CVE-2023-3179](https://insights.sbomify.com/CVE-2023-3179/): POST SMTP Mailer < 2.5.7 - Account Takeover via CSRF (high 8.8)
- [CVE-2023-52233](https://insights.sbomify.com/CVE-2023-52233/): WordPress POST SMTP Mailer plugin <= 2.8.6 - Broken Access Control on API vulnerability (high 8.6)
- [CVE-2024-52436](https://insights.sbomify.com/CVE-2024-52436/): WordPress Post SMTP plugin <= 2.9.9 - SQL Injection vulnerability (high 7.6)
- [CVE-2025-0521](https://insights.sbomify.com/CVE-2025-0521/): Post SMTP <= 3.0.2 - Unauthenticated Stored Cross-Site Scripting (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4422 and fix it if it is affected.

What it is: CVE-2021-4422 is a medium-severity vulnerability in saadiqbal Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App, published on 12 Jul 2023. 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-2021-4422 in the wild and no public exploit code.

Affected product: saadiqbal Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App. 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-2021-4422/ (Markdown: https://insights.sbomify.com/CVE-2021-4422/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4422
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4422
- OSV: https://osv.dev/vulnerability/CVE-2021-4422

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-4422/
Summaries are generated and may contain mistakes; the official description above is the record.