# CVE-2021-42194: XML external entity in n/a

> An attacker can exploit an XML External Entity vulnerability in EyouCms to read sensitive files or cause denial of service.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Mar 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-7qfq-q2rc-5r96

## What is CVE-2021-42194?

CVE-2021-42194 is a high-severity vulnerability in Eyoucms Eyoucms, published on 20 Mar 2022. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The wechat_return function in /controller/Index.php of EyouCms V1.5.4-UTF8-SP3 passes the user's input directly into the simplexml_ load_ String function, which itself does not prohibit external entities, triggering a XML external entity (XXE) injection vulnerability.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference)

## Which versions are affected by CVE-2021-42194?

It affects 1 product.


Products: Eyoucms Eyoucms.

## How do I fix CVE-2021-42194?

No fix has been published for CVE-2021-42194 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42194 being exploited?

There is no known exploitation of CVE-2021-42194 in the wild and no public exploit code.

## Other vulnerabilities in Eyoucms Eyoucms

- [CVE-2023-42286](https://insights.sbomify.com/CVE-2023-42286/): File upload in n/a (critical 9.8)
- [CVE-2022-26273](https://insights.sbomify.com/CVE-2022-26273/): Business logic in n/a (critical 9.8)
- [CVE-2022-26279](https://insights.sbomify.com/CVE-2022-26279/): Missing authorization in n/a (critical 9.8)
- [CVE-2020-24000](https://insights.sbomify.com/CVE-2020-24000/): SQL injection in n/a (critical 9.8)
- [CVE-2021-39497](https://insights.sbomify.com/CVE-2021-39497/): Server-side request forgery in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42194 and fix it if it is affected.

What it is: CVE-2021-42194 is a high-severity vulnerability in Eyoucms Eyoucms, published on 20 Mar 2022. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-42194 in the wild and no public exploit code.

Affected product: Eyoucms Eyoucms. 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-2021-42194/ (Markdown: https://insights.sbomify.com/CVE-2021-42194/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42194
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42194
- OSV: https://osv.dev/vulnerability/CVE-2021-42194

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42194/
Summaries are generated and may contain mistakes; the official description above is the record.