CVE-2023-42669

Samba: "rpcecho" development server allows denial of service via sleep() call on ad dc

publishedCWE-400

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.

Technical severity6.5 mediumCVSS 3.1 · CNA: redhat

Published2023-11-06Source updated 2026-11-07

Collected2026-11-072 attributed sources

Fixes and workarounds

Workaround

To mitigate this vulnerability, disable rpcecho service on the AD DC by setting: ~~~ dcerpc endpoint servers = -rpcecho ~~~

Source: CNA: redhat

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
`samba` https://github.com/samba-team/samba	≥ 4.0.0; < 4.17.12 (affected, semver) ≥ 4.18.0; < 4.18.8 (affected, semver) 4.19.0 (affected) Other versions: unaffected	CNA: redhat
Red Hat Enterprise Linux 8 Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.18.6-2.el8_9; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.6 Extended Update Support Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.15.5-13.el8_6; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 8.8 Extended Update Support Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.17.5-4.el8_8; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9 Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.18.6-101.el9_3; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9.0 Extended Update Support Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.15.5-111.el9_0; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 9.2 Extended Update Support Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.17.5-104.el9_2; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	≥ 0:4.15.5-13.el8_6; < * (unaffected, rpm) Other versions: affected	CNA: redhat
Red Hat Enterprise Linux 6 Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 6 Red Hat `samba4` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Enterprise Linux 7 Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat
Red Hat Storage 3 Red Hat `samba` https://access.redhat.com/downloads/content/package-browser/	Range not reported Other versions: unknown	CNA: redhat

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
3.1 / 6.5 medium	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`	CNA: redhat

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://access.redhat.com/errata/RHSA-2023:6209CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2023:6744CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2023:7371CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2023:7408CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2023:7464CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2023:7467CNA: redhat · vendor-advisory, x_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2023-42669CNA: redhat · vdb-entry, x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2241884CNA: redhat · issue-tracking, x_refsource_REDHAT
https://bugzilla.samba.org/show_bug.cgi?id=15474CNA: redhat
https://www.samba.org/samba/security/CVE-2023-42669.htmlCNA: redhat
https://access.redhat.com/errata/RHSA-2023:6209ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/errata/RHSA-2023:6744ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/errata/RHSA-2023:7371ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/errata/RHSA-2023:7408ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/errata/RHSA-2023:7464ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/errata/RHSA-2023:7467ADP: CVE · vendor-advisory, x_refsource_REDHAT, x_transferred
https://access.redhat.com/security/cve/CVE-2023-42669ADP: CVE · vdb-entry, x_refsource_REDHAT, x_transferred
https://bugzilla.redhat.com/show_bug.cgi?id=2241884ADP: CVE · issue-tracking, x_refsource_REDHAT, x_transferred
https://bugzilla.samba.org/show_bug.cgi?id=15474ADP: CVE · x_transferred
https://security.netapp.com/advisory/ntap-20231124-0002/ADP: CVE · x_transferred
https://www.samba.org/samba/security/CVE-2023-42669.htmlADP: CVE · x_transferred

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