# CVE-2023-40589: FreeRDP Global-Buffer-Overflow in ncrush_decompress

> A global buffer overflow in FreeRDP's ncrush_decompress function allows attackers to cause a crash via crafted input.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 31 Aug 2023
- **Updated:** 3 Nov 2025
- **Also known as:** DEBIAN-CVE-2023-40589, GHSA-gc34-mw6m-g42x, UBUNTU-CVE-2023-40589

## What is CVE-2023-40589?

CVE-2023-40589 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 31 Aug 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions there is a Global-Buffer-Overflow in the ncrush_decompress function. Feeding crafted input into this function can trigger the overflow which has only been shown to cause a crash. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2023-40589?

It affects 3 products.


Products: Debian Debian Linux, Fedoraproject Fedora, Freerdp Freerdp.

## How do I fix CVE-2023-40589?

Upgrade to a fixed version.

## Is CVE-2023-40589 being exploited?

There is no known exploitation of CVE-2023-40589 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-40589 and fix it if it is affected.

What it is: CVE-2023-40589 is a medium-severity memory corruption vulnerability in Debian Debian Linux, published on 31 Aug 2023. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2023-40589 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2023-40589/ (Markdown: https://insights.sbomify.com/CVE-2023-40589/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-40589
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-40589
- OSV: https://osv.dev/vulnerability/CVE-2023-40589

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-40589/
Summaries are generated and may contain mistakes; the official description above is the record.