# CVE-2023-6875: Auth bypass in Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App

> Unauthenticated attackers can bypass authorization via type juggling to reset API keys and view logs, potentially leading to site takeover.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jan 2024
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-9cw8-p5p2-35pf

## What is CVE-2023-6875?

CVE-2023-6875 is a critical authentication bypass vulnerability in saadiqbal Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App, published on 11 Jan 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The POST SMTP Mailer – Email log, Delivery Failure Notifications and Best Mail SMTP for WordPress plugin for WordPress is vulnerable to unauthorized access of data and modification of data due to a type juggling issue on the connect-app REST endpoint in all versions up to, and including, 2.8.7. This makes it possible for unauthenticated attackers to reset the API key used to authenticate to the mailer and view logs, including password reset emails, allowing site takeover. CVE-2023-52233 appears to be a duplicate of this issue.

Weakness: CWE-862 (Missing Authorization), CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2023-6875?

It affects 1 product.


Products: Wpexperts Post Smtp.

## How do I fix CVE-2023-6875?

No fix has been published for CVE-2023-6875 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-6875 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-6875 exists.

Public exploit code:

- CVE-2023-6875 PoC (github_poc): https://github.com/UlyssesSaicha/CVE-2023-6875
- Exploit for CVE-2023-6875 - Unauthorized Account Takeover.  (github_poc): https://github.com/gbrsh/CVE-2023-6875
- CVE-2023-6875 exploit written for Xakep.Ru (github_poc): https://github.com/hatlesswizard/CVE-2023-6875
- Wordpress POST SMTP Account Takeover (metasploit)
- WordPress POST SMTP Mailer <= 2.8.7 - Authorization Bypass (nuclei): http/cves/2023/CVE-2023-6875.yaml

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

- [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)
- [CVE-2024-5207](https://insights.sbomify.com/CVE-2024-5207/): SQL injection in Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-6875 and fix it if it is affected.

What it is: CVE-2023-6875 is a critical authentication bypass vulnerability in saadiqbal Post SMTP – Complete Email Deliverability and SMTP Solution with Email Logs, Alerts, Backup SMTP & Mobile App, published on 11 Jan 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-6875 exists.

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-2023-6875/ (Markdown: https://insights.sbomify.com/CVE-2023-6875/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-6875
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-6875
- OSV: https://osv.dev/vulnerability/CVE-2023-6875

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From sbomify Insights: https://insights.sbomify.com/CVE-2023-6875/
Summaries are generated and may contain mistakes; the official description above is the record.