# CVE-2017-12800: Null dereference in n/a

> Remote attackers can cause a denial of service via a crafted MKV file due to a null pointer dereference in libebml2.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Nov 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-jf99-2h2p-q9x7

## What is CVE-2017-12800?

CVE-2017-12800 is a medium-severity vulnerability in n/a, published on 9 Nov 2017. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

The EBML_FindNextElement function in ebmlmain.c in libebml2 through 2012-08-26 allows remote attackers to cause a denial of service (Null pointer dereference and application crash) via a crafted mkv file.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2017-12800?

It affects 3 products.


Products: Matroska Libebml2, Matroska Mkclean, Matroska Mkvalidator.

## How do I fix CVE-2017-12800?

No fix has been published for CVE-2017-12800 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-12800 being exploited?

There is no known exploitation of CVE-2017-12800 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2017-12780](https://insights.sbomify.com/CVE-2017-12780/): Use after free in n/a (medium 6.5)
- [CVE-2017-12781](https://insights.sbomify.com/CVE-2017-12781/): Null dereference in n/a (medium 6.5)
- [CVE-2017-12782](https://insights.sbomify.com/CVE-2017-12782/): Denial of service in n/a (medium 6.5)
- [CVE-2017-12783](https://insights.sbomify.com/CVE-2017-12783/): Denial of service in n/a (medium 6.5)
- [CVE-2017-12801](https://insights.sbomify.com/CVE-2017-12801/): Denial of service in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-12800 and fix it if it is affected.

What it is: CVE-2017-12800 is a medium-severity vulnerability in n/a, published on 9 Nov 2017. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2017-12800 in the wild and no public exploit code.

Affected product: n/a. 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-2017-12800/ (Markdown: https://insights.sbomify.com/CVE-2017-12800/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-12800
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-12800
- OSV: https://osv.dev/vulnerability/CVE-2017-12800

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-12800/
Summaries are generated and may contain mistakes; the official description above is the record.