# CVE-2021-24307: All in One SEO Pack < 4.1.0.2 - Admin RCE via unserialize

> Authenticated administrators can execute arbitrary code via unsafe deserialization of uploaded backup files in the All in One SEO WordPress plugin.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-fg47-8fhh-p6fc

## What is CVE-2021-24307?

CVE-2021-24307 is a high-severity unsafe deserialization vulnerability in All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings, published on 24 May 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings before 4.1.0.2 enables authenticated users with "aioseo_tools_settings" privilege (most of the time admin) to execute arbitrary code on the underlying host. Users can restore plugin's configuration by uploading a backup .ini file in the section "Tool > Import/Export". However, the plugin attempts to unserialize values of the .ini file. Moreover, the plugin embeds Monolog library which can be used to craft a gadget chain and thus trigger system command execution.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2021-24307?

It affects 1 product.


Products: Aioseo All in One Seo.

## How do I fix CVE-2021-24307?

No fix has been published for CVE-2021-24307 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-24307 being exploited?

There is no known exploitation of CVE-2021-24307 in the wild and no public exploit code.

Public exploit code:

- https://github.com/darkpills/CVE-2021-24307-all-in-one-seo-pack-admin-rce (github_poc): https://github.com/darkpills/CVE-2021-24307-all-in-one-seo-pack-admin-rce

## Other vulnerabilities in All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings

- [CVE-2021-25036](https://insights.sbomify.com/CVE-2021-25036/): All In One SEO < 4.1.5.3 - Authenticated Privilege Escalation (high 8.8)
- [CVE-2021-25037](https://insights.sbomify.com/CVE-2021-25037/): All In One SEO < 4.1.5.3 - Authenticated SQL Injection (medium 6.5)
- [CVE-2025-2892](https://insights.sbomify.com/CVE-2025-2892/): Cross-site scripting in All in One SEO – Powerful SEO Plugin to Boost SEO Rankings & Increase Traffic (medium 6.4)
- [CVE-2024-3554](https://insights.sbomify.com/CVE-2024-3554/): Cross-site scripting in All in One SEO – Powerful SEO Plugin to Boost SEO Rankings & Increase Traffic (medium 6.4)
- [CVE-2023-0586](https://insights.sbomify.com/CVE-2023-0586/): All in One SEO Pack <= 4.2.9 - Authenticated (Contributor+) Stored Cross-Site Scripting (medium 6.4)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-24307 and fix it if it is affected.

What it is: CVE-2021-24307 is a high-severity unsafe deserialization vulnerability in All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings, published on 24 May 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-24307 in the wild and no public exploit code.

Affected product: All in One SEO – Best WordPress SEO Plugin – Easily Improve Your SEO Rankings. 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-2021-24307/ (Markdown: https://insights.sbomify.com/CVE-2021-24307/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-24307
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-24307
- OSV: https://osv.dev/vulnerability/CVE-2021-24307

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-24307/
Summaries are generated and may contain mistakes; the official description above is the record.