# CVE-2021-3312: XML External Entity Reference in org.opencms:opencms-core

> Authenticated users with edit privileges can exfiltrate server files via crafted SVG documents in OpenCms.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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:** 8 Oct 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-g6v7-vqhx-6v6c

## What is CVE-2021-3312?

CVE-2021-3312 is a medium-severity vulnerability in n/a, published on 8 Oct 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An XML external entity (XXE) vulnerability in Alkacon OpenCms 11.0, 11.0.1 and 11.0.2 allows remote authenticated users with edit privileges to exfiltrate files from the server's file system by uploading a crafted SVG document.

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

## Which versions are affected by CVE-2021-3312?

2 open source packages ship an affected version, including org.opencms:opencms-core. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.opencms:opencms-core` | Maven | From 11.0.0 | 12.0.0 |
| `org.opencms:opencms-core` | Maven | From 11.0.0 | 12.0.0 |

Products: Alkacon Opencms.

## How do I fix CVE-2021-3312?

Upgrade org.opencms:opencms-core to 12.0.0 or later.

## Is CVE-2021-3312 being exploited?

There is no known exploitation of CVE-2021-3312 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-8811](https://insights.sbomify.com/CVE-2018-8811/): Cross-site request forgery in n/a (high 8.8)
- [CVE-2019-11819](https://insights.sbomify.com/CVE-2019-11819/): Alkacon OpenCMS CSV Injection via New User module (high 7.8)
- [CVE-2005-4475](https://insights.sbomify.com/CVE-2005-4475/): Cross-site scripting in n/a (medium 6.8)
- [CVE-2024-42699](https://insights.sbomify.com/CVE-2024-42699/): OpenCMS Cross-Site Scripting vulnerability (medium 6.5)
- [CVE-2006-3935](https://insights.sbomify.com/CVE-2006-3935/): Alkacon OpenCMS Improper Access Control via system/workplace/views/admin/admin-main.jsp (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3312 and fix it if it is affected.

What it is: CVE-2021-3312 is a medium-severity vulnerability in n/a, published on 8 Oct 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-2021-3312 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.opencms:opencms-core (Maven): affected from 11.0.0; fixed in 12.0.0
- org.opencms:opencms-core (Maven): affected from 11.0.0; fixed in 12.0.0

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-2021-3312/ (Markdown: https://insights.sbomify.com/CVE-2021-3312/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3312
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3312
- OSV: https://osv.dev/vulnerability/CVE-2021-3312

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3312/
Summaries are generated and may contain mistakes; the official description above is the record.