# CVE-2023-42669: Samba: "rpcecho" development server allows denial of service via sleep() call on ad dc

> Authenticated attackers can cause a complete denial of service on Samba Active Directory Domain Controllers by exploiting the rpcecho development server.

- **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:** 6 Nov 2023
- **Updated:** 20 Nov 2025
- **Also known as:** ALPINE-CVE-2023-42669, AZL-31940, AZL-37027, CLSA-2026-1778879662, CLSA-2026-1778881275, DEBIAN-CVE-2023-42669, ECHO-ec2c-9974-e837, GHSA-8q58-8vm2-mf3q, UBUNTU-CVE-2023-42669

## What is CVE-2023-42669?

CVE-2023-42669 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 6 Nov 2023. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability was found in Samba's "rpcecho" development server, a non-Windows RPC server used to test Samba's DCE/RPC stack elements. This vulnerability stems from an RPC function that can be blocked indefinitely. The issue arises because the "rpcecho" service operates with only one worker in the main RPC task, allowing calls to the "rpcecho" server to be blocked for a specified time, causing service disruptions. This disruption is triggered by a "sleep()" call in the "dcesrv_echo_TestSleep()" function under specific conditions. Authenticated users or attackers can exploit this vulnerability to make calls to the "rpcecho" server, requesting it to block for a specified duration, effectively disrupting most services and leading to a complete denial of service on the AD DC. The DoS affects all other services as "rpcecho" runs in the main RPC task.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2023-42669?

It affects 8 products.


Products: Redhat Enterprise Linux, Redhat Enterprise Linux Eus, Redhat Enterprise Linux for Ibm Z Systems, Redhat Enterprise Linux for Ibm Z Systems Eus, Redhat Enterprise Linux for Power Little Endian, Redhat Enterprise Linux for Power Little Endian Eus, Redhat Storage, Samba Samba.

## How do I fix CVE-2023-42669?

Apply the vendor's patch.

## Is CVE-2023-42669 being exploited?

There is no known exploitation of CVE-2023-42669 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Enterprise Linux

- [CVE-2018-14667](https://insights.sbomify.com/CVE-2018-14667/): Red Hat JBoss RichFaces Framework Expression Language Injection (critical 9.8, exploited in the wild)
- [CVE-2021-20325](https://insights.sbomify.com/CVE-2021-20325/): Missing fixes for CVE-2021-40438 and CVE-2021-26691 in the versions of httpd, as shipped in Red Hat Enterprise Linux 8.5.0, causes a securit (critical 9.8)
- [CVE-2018-25011](https://insights.sbomify.com/CVE-2018-25011/): Memory corruption in libwebp (critical 9.8)
- [CVE-2018-25014](https://insights.sbomify.com/CVE-2018-25014/): Other in libwebp (critical 9.8)
- [CVE-2014-3585](https://insights.sbomify.com/CVE-2014-3585/): Supply chain in redhat-upgrade-tool (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-42669 and fix it if it is affected.

What it is: CVE-2023-42669 is a medium-severity denial of service vulnerability in Redhat Enterprise Linux, published on 6 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-2023-42669 in the wild and no public exploit code.

Affected product: Redhat Enterprise 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-2023-42669/ (Markdown: https://insights.sbomify.com/CVE-2023-42669/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-42669
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-42669
- OSV: https://osv.dev/vulnerability/CVE-2023-42669

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-42669/
Summaries are generated and may contain mistakes; the official description above is the record.