# CVE-2023-42670: Samba: ad dc busy rpc multiple listener dos

> An attacker can disrupt Active Directory Domain Controller services by triggering incompatible RPC listeners, causing service unresponsiveness and partial query failures.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 3 Nov 2023
- **Updated:** 20 Nov 2025
- **Also known as:** ALPINE-CVE-2023-42670, AZL-31901, AZL-37028, DEBIAN-CVE-2023-42670, ECHO-9e4d-e76a-7140, GHSA-5qvm-gfmw-9v64, UBUNTU-CVE-2023-42670

## What is CVE-2023-42670?

CVE-2023-42670 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 3 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw was found in Samba. It is susceptible to a vulnerability where multiple incompatible RPC listeners can be initiated, causing disruptions in the AD DC service. When Samba's RPC server experiences a high load or unresponsiveness, servers intended for non-AD DC purposes (for example, NT4-emulation "classic DCs") can erroneously start and compete for the same unix domain sockets. This issue leads to partial query responses from the AD DC, causing issues such as "The procedure number is out of range" when using tools like Active Directory Users. This flaw allows an attacker to disrupt AD DC services.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2023-42670?

It affects 2 products.


Products: Fedoraproject Fedora, Samba Samba.

## How do I fix CVE-2023-42670?

Apply the vendor's patch.

## Is CVE-2023-42670 being exploited?

There is no known exploitation of CVE-2023-42670 in the wild and no public exploit code.

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- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-42670 and fix it if it is affected.

What it is: CVE-2023-42670 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 3 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-42670 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2023-42670/ (Markdown: https://insights.sbomify.com/CVE-2023-42670/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-42670
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-42670
- OSV: https://osv.dev/vulnerability/CVE-2023-42670

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-42670/
Summaries are generated and may contain mistakes; the official description above is the record.