# CVE-2023-40576: Out-Of-Bounds Read in FreeRDP

> An out-of-bounds read in FreeRDP's RleDecompress function can cause application crashes, requiring users to upgrade to a patched version.

- **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:** 13 Feb 2025
- **Also known as:** GHSA-x3x5-r7jm-5pq2

## What is CVE-2023-40576?

CVE-2023-40576 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, 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 Out-Of-Bounds Read in the `RleDecompress` function. This Out-Of-Bounds Read occurs because FreeRDP processes the `pbSrcBuffer` variable without checking if it contains data of sufficient length. Insufficient data in the `pbSrcBuffer` variable may cause errors or crashes. This issue has been addressed in version 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2023-40576?

It affects 1 product.


Products: Freerdp Freerdp.

## How do I fix CVE-2023-40576?

Upgrade to a fixed version.

## Is CVE-2023-40576 being exploited?

There is no known exploitation of CVE-2023-40576 in the wild and no public exploit code.

## Other vulnerabilities in Freerdp Freerdp

- [CVE-2021-37594](https://insights.sbomify.com/CVE-2021-37594/): Other in n/a (critical 9.8)
- [CVE-2021-37595](https://insights.sbomify.com/CVE-2021-37595/): Other in n/a (critical 9.8)
- [CVE-2026-67305](https://insights.sbomify.com/CVE-2026-67305/): FreeRDP Windows Client before 3.29.0 Heap Buffer Overflow via Cliprdr (critical 9.4)
- [CVE-2026-66402](https://insights.sbomify.com/CVE-2026-66402/): FreeRDP before 3.29.0 TLS Certificate Identity Validation Bypass (critical 9.3)
- [CVE-2026-67289](https://insights.sbomify.com/CVE-2026-67289/): FreeRDP before 3.29.0 HTTP Proxy Request Injection via Redirection (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-40576 and fix it if it is affected.

What it is: CVE-2023-40576 is a medium-severity memory corruption vulnerability in Freerdp Freerdp, 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-2023-40576 in the wild and no public exploit code.

Affected product: Freerdp Freerdp. 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-2023-40576/ (Markdown: https://insights.sbomify.com/CVE-2023-40576/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-40576
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-40576
- OSV: https://osv.dev/vulnerability/CVE-2023-40576

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-40576/
Summaries are generated and may contain mistakes; the official description above is the record.