# CVE-2018-6641: Use after free in n/a

> Crafted input in MathType triggers a use-after-free, allowing remote attackers to execute arbitrary code via invalid function pointer calls.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Feb 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-p4xx-95p7-3998

## What is CVE-2018-6641?

CVE-2018-6641 is a critical use after free vulnerability in n/a, published on 28 Feb 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An Arbitrary Free (Remote Code Execution) issue was discovered in Design Science MathType 6.9c. Crafted input can overwrite a structure, leading to a function call with an invalid parameter, and a subsequent free of important data such as a function pointer or list pointer. This is fixed in 6.9d.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2018-6641?

It affects 1 product.


Products: Wiris Mathtype.

## How do I fix CVE-2018-6641?

No fix has been published for CVE-2018-6641 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-6641 being exploited?

There is no known exploitation of CVE-2018-6641 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-6638](https://insights.sbomify.com/CVE-2018-6638/): Memory corruption in n/a (critical 9.8)
- [CVE-2018-6639](https://insights.sbomify.com/CVE-2018-6639/): Memory corruption in n/a (critical 9.8)
- [CVE-2018-6640](https://insights.sbomify.com/CVE-2018-6640/): Memory corruption in n/a (critical 9.8)
- [CVE-2022-31372](https://insights.sbomify.com/CVE-2022-31372/): Path traversal in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-6641 and fix it if it is affected.

What it is: CVE-2018-6641 is a critical use after free vulnerability in n/a, published on 28 Feb 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-2018-6641 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-2018-6641/ (Markdown: https://insights.sbomify.com/CVE-2018-6641/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-6641
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-6641
- OSV: https://osv.dev/vulnerability/CVE-2018-6641

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-6641/
Summaries are generated and may contain mistakes; the official description above is the record.