# CVE-2023-40181: Integer-Underflow leading to Out-Of-Bound Read in FreeRDP

> An integer underflow in FreeRDP allows out-of-bounds reads, potentially causing a crash during RDP session decompression.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** Yes
- **Published:** 31 Aug 2023
- **Updated:** 3 Nov 2025
- **Also known as:** DEBIAN-CVE-2023-40181, GHSA-mxp4-rx7x-h2g8, UBUNTU-CVE-2023-40181

## What is CVE-2023-40181?

CVE-2023-40181 is a medium-severity vulnerability in Debian Debian Linux, published on 31 Aug 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Integer-Underflow leading to Out-Of-Bound Read in the `zgfx_decompress_segment` function. In the context of `CopyMemory`, it's possible to read data beyond the transmitted packet range and likely 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-191 (Integer Underflow (Wrap or Wraparound)), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2023-40181?

It affects 3 products.


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

## How do I fix CVE-2023-40181?

Upgrade to a fixed version.

## Is CVE-2023-40181 being exploited?

There is no known exploitation of CVE-2023-40181 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-2023-40181 and fix it if it is affected.

What it is: CVE-2023-40181 is a medium-severity vulnerability in Debian Debian Linux, published on 31 Aug 2023. 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-2023-40181 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-2023-40181/ (Markdown: https://insights.sbomify.com/CVE-2023-40181/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-40181
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-40181
- OSV: https://osv.dev/vulnerability/CVE-2023-40181

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-40181/
Summaries are generated and may contain mistakes; the official description above is the record.