# CVE-2018-1000821: XML external entity in n/a

> Attackers can exploit XML External Entity vulnerabilities in SMath Studio files to disclose confidential data or cause denial of service.

- **Severity:** Critical 10.0 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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:** 20 Dec 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-7q84-r8xm-hp4c

## What is CVE-2018-1000821?

CVE-2018-1000821 is a critical vulnerability in n/a, published on 20 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

MicroMathematics version before commit 5c05ac8 contains a XML External Entity (XXE) vulnerability in SMathStudio files that can result in Disclosure of confidential data, denial of service, SSRF, port scanning. This attack appear to be exploitable via Specially crafted SMathStudio files. This vulnerability appears to have been fixed in after commit 5c05ac8.

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

## Which versions are affected by CVE-2018-1000821?

It affects 1 product.


Products: Micromathematics Project Micromathematics.

## How do I fix CVE-2018-1000821?

No fix has been published for CVE-2018-1000821 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-1000821 being exploited?

There is no known exploitation of CVE-2018-1000821 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1000821 and fix it if it is affected.

What it is: CVE-2018-1000821 is a critical vulnerability in n/a, published on 20 Dec 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-2018-1000821 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-2018-1000821/ (Markdown: https://insights.sbomify.com/CVE-2018-1000821/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1000821
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1000821
- OSV: https://osv.dev/vulnerability/CVE-2018-1000821

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1000821/
Summaries are generated and may contain mistakes; the official description above is the record.