# CVE-2020-36773: Use after free in n/a

> Attackers can trigger a use-after-free and out-of-bounds write in Ghostscript via crafted PDFs, potentially leading to code execution or crashes.

- **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:** Yes
- **Published:** 4 Feb 2024
- **Updated:** 22 May 2025
- **Also known as:** DEBIAN-CVE-2020-36773, GHSA-mwx2-8cmg-6vmj, OESA-2024-1462, OESA-2024-1463, SUSE-SU-2024:0920-1, SUSE-SU-2024:0921-1

## What is CVE-2020-36773?

CVE-2020-36773 is a critical use after free vulnerability in Artifex Ghostscript, published on 4 Feb 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Artifex Ghostscript before 9.53.0 has an out-of-bounds write and use-after-free in devices/vector/gdevtxtw.c (for txtwrite) because a single character code in a PDF document can map to more than one Unicode code point (e.g., for a ligature).

Weakness: CWE-787 (Out-of-bounds Write), CWE-416 (Use After Free)

## Which versions are affected by CVE-2020-36773?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `ghostscript` | SUSE:Linux Enterprise Module for Basesystem 15 SP5 | All versions | 9.52-150000.185.1 |
| `ghostscript` | SUSE:Linux Enterprise Server 12 SP5 | All versions | 9.52-23.71.1 |
| `ghostscript` | SUSE:Linux Enterprise Server for SAP Applications 12 SP5 | All versions | 9.52-23.71.1 |
| `ghostscript` | SUSE:Linux Enterprise Software Development Kit 12 SP5 | All versions | 9.52-23.71.1 |
| `ghostscript` | openSUSE:Leap 15.5 | All versions | 9.52-150000.185.1 |

Products: Artifex Ghostscript.

## How do I fix CVE-2020-36773?

Upgrade to a fixed version.

## Is CVE-2020-36773 being exploited?

There is no known exploitation of CVE-2020-36773 in the wild and no public exploit code.

## 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-2020-36773 and fix it if it is affected.

What it is: CVE-2020-36773 is a critical use after free vulnerability in Artifex Ghostscript, published on 4 Feb 2024. 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-2020-36773 in the wild and no public exploit code.

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-2020-36773/ (Markdown: https://insights.sbomify.com/CVE-2020-36773/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36773
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36773
- OSV: https://osv.dev/vulnerability/CVE-2020-36773

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36773/
Summaries are generated and may contain mistakes; the official description above is the record.