# CVE-2021-31779: Server-Side Request Forgery in yoast_seo

> An attacker with a backend account can exploit Server-Side Request Forgery in the Yoast SEO extension to access internal resources.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 28 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-m2q4-qghh-p9cq

## What is CVE-2021-31779?

CVE-2021-31779 is a medium-severity server-side request forgery vulnerability in n/a, published on 28 Apr 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The yoast_seo (aka Yoast SEO) extension before 7.2.1 for TYPO3 allows SSRF via a backend user account.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2021-31779?

2 open source packages ship an affected version, including yoast-seo-for-typo3/yoast_seo. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `yoast-seo-for-typo3/yoast_seo` | Packagist | All versions | 7.2.1 |
| `yoast-seo-for-typo3/yoast_seo` | Packagist | All versions | 7.2.1 |

Products: Yoast Yoast Seo.

## How do I fix CVE-2021-31779?

Upgrade yoast-seo-for-typo3/yoast_seo to 7.2.1 or later.

## Is CVE-2021-31779 being exploited?

There is no known exploitation of CVE-2021-31779 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2019-13478](https://insights.sbomify.com/CVE-2019-13478/): Cross-site scripting in n/a (critical 9.9)
- [CVE-2023-32300](https://insights.sbomify.com/CVE-2023-32300/): WordPress Yoast SEO: Local Plugin <= 14.8 is vulnerable to Cross Site Scripting (XSS) (high 7.1)
- [CVE-2018-19370](https://insights.sbomify.com/CVE-2018-19370/): Race condition in n/a (medium 6.6)
- [CVE-2023-28785](https://insights.sbomify.com/CVE-2023-28785/): WordPress Yoast SEO: Local Plugin <= 14.9 is vulnerable to Cross Site Scripting (XSS) (medium 6.5)
- [CVE-2023-40680](https://insights.sbomify.com/CVE-2023-40680/): WordPress Yoast SEO Plugin <= 21.0 is vulnerable to Cross Site Scripting (XSS) (medium 5.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31779 and fix it if it is affected.

What it is: CVE-2021-31779 is a medium-severity server-side request forgery vulnerability in n/a, published on 28 Apr 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-2021-31779 in the wild and no public exploit code.

Affected packages and fixed versions:
- yoast-seo-for-typo3/yoast_seo (Packagist): affected all versions; fixed in 7.2.1
- yoast-seo-for-typo3/yoast_seo (Packagist): affected all versions; fixed in 7.2.1

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-2021-31779/ (Markdown: https://insights.sbomify.com/CVE-2021-31779/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31779
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31779
- OSV: https://osv.dev/vulnerability/CVE-2021-31779

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31779/
Summaries are generated and may contain mistakes; the official description above is the record.