# CVE-2021-28927: Command injection in n/a

> Attackers with filesystem write access can execute arbitrary code via command injection in RetroArch's Windows text-to-speech engine.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Apr 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-7585-2mwm-5jvf

## What is CVE-2021-28927?

CVE-2021-28927 is a high-severity command injection vulnerability in n/a, published on 7 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The text-to-speech engine in libretro RetroArch for Windows 1.9.0 passes unsanitized input to PowerShell through platform_win32.c via the accessibility_speak_windows function, which allows attackers who have write access on filesystems that are used by RetroArch to execute code via command injection using specially a crafted file and directory names.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2021-28927?

It affects 1 product.


Products: Libretro Retroarch.

## How do I fix CVE-2021-28927?

No fix has been published for CVE-2021-28927 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-28927 being exploited?

There is no known exploitation of CVE-2021-28927 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2025-9136](https://insights.sbomify.com/CVE-2025-9136/): libretro RetroArch file_stream.c filestream_vscanf out-of-bounds (medium 4.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28927 and fix it if it is affected.

What it is: CVE-2021-28927 is a high-severity command injection vulnerability in n/a, published on 7 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-28927 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-2021-28927/ (Markdown: https://insights.sbomify.com/CVE-2021-28927/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28927
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28927
- OSV: https://osv.dev/vulnerability/CVE-2021-28927

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28927/
Summaries are generated and may contain mistakes; the official description above is the record.