CVE-2023-42669

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

State: Published
Severity: 6.5 Medium
Published: Nov 6, 2023
Updated: Nov 20, 2025
Reserved: Sep 13, 2023

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.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H	redhat

Weaknesses

CWE-400 Uncontrolled Resource Consumption

Affected Products

Product	Versions
samba	4.0.0 to before 4.17.12Affected 4.18.0 to before 4.18.8Affected 4.19.0Affected
Red Hat Enterprise Linux 8Red Hat	0:4.18.6-2.el8_9 and laterNot affected
Red Hat Enterprise Linux 8Red Hat	0:4.18.6-2.el8_9 and laterNot affected
Red Hat Enterprise Linux 8.6 Extended Update SupportRed Hat	0:4.15.5-13.el8_6 and laterNot affected
Red Hat Enterprise Linux 8.8 Extended Update SupportRed Hat	0:4.17.5-4.el8_8 and laterNot affected
Red Hat Enterprise Linux 9Red Hat	0:4.18.6-101.el9_3 and laterNot affected
Red Hat Enterprise Linux 9Red Hat	0:4.18.6-101.el9_3 and laterNot affected
Red Hat Enterprise Linux 9.0 Extended Update SupportRed Hat	0:4.15.5-111.el9_0 and laterNot affected
Red Hat Enterprise Linux 9.2 Extended Update SupportRed Hat	0:4.17.5-104.el9_2 and laterNot affected
Red Hat Virtualization 4 for Red Hat Enterprise Linux 8Red Hat	0:4.15.5-13.el8_6 and laterNot affected
Red Hat Enterprise Linux 6Red Hat
Red Hat Enterprise Linux 6Red Hat
Red Hat Enterprise Linux 7Red Hat
Red Hat Storage 3Red Hat

References

RHSA-2023:6209vendor-advisory
RHSA-2023:6744vendor-advisory
RHSA-2023:7371vendor-advisory
RHSA-2023:7408vendor-advisory
RHSA-2023:7464vendor-advisory
RHSA-2023:7467vendor-advisory
https://access.redhat.com/security/cve/CVE-2023-42669vdb-entry
RHBZ#2241884issue-tracking
https://bugzilla.samba.org/show_bug.cgi?id=15474
https://www.samba.org/samba/security/CVE-2023-42669.html
https://security.netapp.com/advisory/ntap-20231124-0002/

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