---
id: CVE-2023-42670
title: 'Samba: ad dc busy rpc multiple listener dos'
summary: >-
  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,
  se…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
cwe:
  - CWE-400
vendor: Red Hat
product: samba
affected:
  - samba >= 4.16.0 < 4.17.12
  - samba >= 4.18.0 < 4.18.8
  - samba 4.19.0
  - samba
  - samba4
  - samba
  - samba
  - samba
  - samba
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2024-08-29T14:14:50.476521Z'
published: '2023-11-03'
updated: '2026-11-07'
sourceUpdated: '2026-11-07T11:31:56.949Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-42670'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2023-42670'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2241885'
    label: RHBZ#2241885
  - url: 'https://bugzilla.samba.org/show_bug.cgi?id=15473'
  - url: 'https://www.samba.org/samba/security/CVE-2023-42670.html'
tags:
  - cve.org
epss: 0.01317
epssPercentile: 0.70968
ingestedAt: '2026-11-07T12:16:41.117Z'
---

## Overview

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.

## Affected

- `samba >= 4.16.0 < 4.17.12`
- `samba >= 4.18.0 < 4.18.8`
- `samba 4.19.0`
- `samba`
- `samba4`
- `samba`
- `samba`
- `samba`
- `samba`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.