# CVE-2018-14716: SEOmatic plugin for Craft CMS SSTI Vulnerability

> Attacker can execute arbitrary Twig code via Server Side Template Injection in SEOmatic plugin for Craft CMS.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 6 Aug 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-6j9m-rp7m-3gfg

## What is CVE-2018-14716?

CVE-2018-14716 is a high-severity code injection vulnerability in n/a, published on 6 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A Server Side Template Injection (SSTI) was discovered in the SEOmatic plugin before 3.1.4 for Craft CMS, because requests that don't match any elements incorrectly generate the canonicalUrl, and can lead to execution of Twig code.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2018-14716?

2 open source packages ship an affected version, including nystudio107/craft-seomatic. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nystudio107/craft-seomatic` | Packagist | All versions | 3.1.4 |
| `nystudio107/craft-seomatic` | Packagist | All versions | 3.1.4 |

Products: Nystudio107 Seomatic.

## How do I fix CVE-2018-14716?

Upgrade nystudio107/craft-seomatic to 3.1.4 or later.

## Is CVE-2018-14716 being exploited?

There is no known exploitation of CVE-2018-14716 in the wild and no public exploit code.

Public exploit code:

- PoC for CVE-2018-14716 (github_poc): https://github.com/0xB455/CVE-2018-14716
- Craft CMS SEOmatic plugin 3.1.4 - Server-Side Template Injection (exploitdb)

## Other vulnerabilities in n/a

- [CVE-2021-41749](https://insights.sbomify.com/CVE-2021-41749/): Code Injection in SEOmatic (critical 9.8)
- [CVE-2021-44618](https://insights.sbomify.com/CVE-2021-44618/): Server-side Template Injection in nystudio107/craft-seomatic (critical 9.8)
- [CVE-2020-12790](https://insights.sbomify.com/CVE-2020-12790/): SEOmatic for CraftCMS allows Server-Side Template Injection (high 7.5)
- [CVE-2021-41750](https://insights.sbomify.com/CVE-2021-41750/): Cross-site Scripting in SEOmatic plugin (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-14716 and fix it if it is affected.

What it is: CVE-2018-14716 is a high-severity code injection vulnerability in n/a, published on 6 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-14716 in the wild and no public exploit code.

Affected packages and fixed versions:
- nystudio107/craft-seomatic (Packagist): affected all versions; fixed in 3.1.4
- nystudio107/craft-seomatic (Packagist): affected all versions; fixed in 3.1.4

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-2018-14716/ (Markdown: https://insights.sbomify.com/CVE-2018-14716/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-14716
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-14716
- OSV: https://osv.dev/vulnerability/CVE-2018-14716

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-14716/
Summaries are generated and may contain mistakes; the official description above is the record.