# CVE-2021-43807: HTTP Method Spoofing in Opencast


- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 14 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-j4mm-7pj3-jf7v

## What is CVE-2021-43807?

CVE-2021-43807 is a high-severity vulnerability in opencast, published on 14 Dec 2021. 

### Official description

Opencast is an Open Source Lecture Capture & Video Management for Education. Opencast versions prior to 9.10 allow HTTP method spoofing, allowing to change the assumed HTTP method via URL parameter. This allows attackers to turn HTTP GET requests into PUT requests or an HTTP form to send DELETE requests. This bypasses restrictions otherwise put on these types of requests and aids in cross-site request forgery (CSRF) attacks, which would otherwise not be possible. The vulnerability allows attackers to craft links or forms which may change the server state. This issue is fixed in Opencast 9.10 and 10.0. You can mitigate the problem by setting the `SameSite=Strict` attribute for your cookies. If this is a viable option for you depends on your integrations. We strongly recommend updating in any case.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2021-43807?

2 open source packages ship an affected version, including org.opencastproject:opencast-common. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.opencastproject:opencast-common` | Maven | All versions | 9.10 |
| `org.opencastproject:opencast-common` | Maven | All versions | 9.10 |

Products: Apereo Opencast.

## How do I fix CVE-2021-43807?

Upgrade org.opencastproject:opencast-common to 9.10 or later.

## Is CVE-2021-43807 being exploited?

There is no known exploitation of CVE-2021-43807 in the wild and no public exploit code.

## Other vulnerabilities in opencast

- [CVE-2021-43821](https://insights.sbomify.com/CVE-2021-43821/): Files Accessible to External Parties in Opencast (critical 9.9)
- [CVE-2020-5206](https://insights.sbomify.com/CVE-2020-5206/): Authentication Bypass For Endpoints With Anonymous Access in OpenCast (high 8.7)
- [CVE-2021-32623](https://insights.sbomify.com/CVE-2021-32623/): Opencast vulnerable to billion laughs attack (XML bomb) (high 8.1)
- [CVE-2020-5229](https://insights.sbomify.com/CVE-2020-5229/): Opencast stores passwords using outdated MD5 hash algorithm (high 7.7)
- [CVE-2020-5230](https://insights.sbomify.com/CVE-2020-5230/): Opencast uses unsafe identifiers (high 7.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-43807 and fix it if it is affected.

What it is: CVE-2021-43807 is a high-severity vulnerability in opencast, published on 14 Dec 2021. 
Exploitation: There is no known exploitation of CVE-2021-43807 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.opencastproject:opencast-common (Maven): affected all versions; fixed in 9.10
- org.opencastproject:opencast-common (Maven): affected all versions; fixed in 9.10

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-2021-43807/ (Markdown: https://insights.sbomify.com/CVE-2021-43807/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-43807
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-43807
- OSV: https://osv.dev/vulnerability/CVE-2021-43807

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-43807/
Summaries are generated and may contain mistakes; the official description above is the record.