# CVE-2020-21890: Memory corruption in n/a

> Remote attackers can cause denial of service or unspecified impacts via crafted PDFs due to a buffer overflow in Ghostscript.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 22 Aug 2023
- **Updated:** 4 Oct 2024
- **Also known as:** DEBIAN-CVE-2020-21890, GHSA-44hq-r6f6-m9g4, UBUNTU-CVE-2020-21890

## What is CVE-2020-21890?

CVE-2020-21890 is a high-severity memory corruption vulnerability in Artifex Ghostscript, published on 22 Aug 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Buffer Overflow vulnerability in clj_media_size function in devices/gdevclj.c in Artifex Ghostscript 9.50 allows remote attackers to cause a denial of service or other unspecified impact(s) via opening of crafted PDF document.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2020-21890?

It affects 1 product.


Products: Artifex Ghostscript.

## How do I fix CVE-2020-21890?

Upgrade to a fixed version.

## Is CVE-2020-21890 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-21890 exists.

## Other vulnerabilities in Artifex Ghostscript

- [CVE-2017-8291](https://insights.sbomify.com/CVE-2017-8291/): Artifex Ghostscript Type Confusion (high 7.8, exploited in the wild)
- [CVE-2021-3781](https://insights.sbomify.com/CVE-2021-3781/): Command injection in ghostscript (critical 9.9)
- [CVE-2025-27831](https://insights.sbomify.com/CVE-2025-27831/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-27832](https://insights.sbomify.com/CVE-2025-27832/): Memory corruption in n/a (critical 9.8)
- [CVE-2025-27836](https://insights.sbomify.com/CVE-2025-27836/): Memory corruption in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-21890 and fix it if it is affected.

What it is: CVE-2020-21890 is a high-severity memory corruption vulnerability in Artifex Ghostscript, published on 22 Aug 2023. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-21890 exists.

Affected product: Artifex Ghostscript. 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-2020-21890/ (Markdown: https://insights.sbomify.com/CVE-2020-21890/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-21890
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-21890
- OSV: https://osv.dev/vulnerability/CVE-2020-21890

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-21890/
Summaries are generated and may contain mistakes; the official description above is the record.