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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | samba | 4.0.0 – < 4.17.12, 4.18.0 – < 4.18.8, 4.19.0 | 4.17.12 |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 8.8 Extended Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 9.0 Extended Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 9.2 Extended Update Support | — | — |
| Red Hat | Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 6 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat Storage 3 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | samba | 2:4.19.1+dfsg-1 | — |
| Debian 13 | samba | 2:4.19.1+dfsg-1 | — |
| Debian 12 | samba | 2:4.17.12+dfsg-0+deb12u1 | DSA-5525-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | samba | 2:4.18.6+dfsg-1ubuntu2.1 | — |
| Ubuntu 22.04 LTS | samba | 2:4.15.13+dfsg-0ubuntu1.5 | USN-6425-1 |
| Ubuntu 20.04 LTS | samba | 2:4.15.13+dfsg-0ubuntu0.20.04.6 | USN-6425-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | samba | No fix yet | — |
| Ubuntu Pro 16.04 LTS | samba | No fix yet | — |
| Ubuntu Pro 14.04 LTS | samba | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | ctdb +33 | 4.18.6-101.el9_3 | RHSA-2023:6744 |
| RHEL 8 | ctdb +33 | 4.18.6-2.el8_9 | RHSA-2023:7467 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Rhev Hypervisor 4 | samba +5 | 4.15.5-13.el8_6 | RHSA-2023:7408 |
| RHEL 9.2 EUS | ctdb +33 | 4.17.5-104.el9_2 | RHSA-2023:7371 |
| RHEL 9.0 EUS | ctdb +23 | 4.15.5-111.el9_0 | RHSA-2023:6209 |
| RHEL 8.8 EUS | ctdb +33 | 4.17.5-4.el8_8 | RHSA-2023:7464 |
| RHEL 8.6 EUS | ctdb +24 | 4.15.5-13.el8_6 | RHSA-2023:7408 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 9 | ctdb +33 | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux 8 | ctdb +33 | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP5 | samba | 4.17.9+git.421.abde31ca5c2-150500.3.11.1 | SUSE-SU-2023:4046-1 |
| SLES 15 SP4 | samba | 4.15.13+git.691.3d3cea0641-150400.3.31.1 | SUSE-SU-2023:4059-1 |
| SLES 15 SP3 | samba | 4.15.13+git.691.3d3cea0641-150300.3.63.1 | SUSE-SU-2023:4096-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP3 | samba | 4.15.13+git.691.3d3cea0641-150300.3.63.1 | SUSE-SU-2023:4096-1 |
| SLE Micro 5.5 | samba | 4.17.9+git.421.abde31ca5c2-150500.3.11.1 | SUSE-SU-2023:4046-1 |
| SLE Micro 5.4 | samba | 4.15.13+git.691.3d3cea0641-150400.3.31.1 | SUSE-SU-2023:4059-1 |
| SLE Micro 5.3 | samba | 4.15.13+git.691.3d3cea0641-150400.3.31.1 | SUSE-SU-2023:4059-1 |
| SLE Micro 5.2 | samba | 4.15.13+git.691.3d3cea0641-150300.3.63.1 | SUSE-SU-2023:4096-1 |
| SLE HPC 15 SP3 | samba | 4.15.13+git.691.3d3cea0641-150300.3.63.1 | SUSE-SU-2023:4096-1 |
| SUSE Manager Server 4.2 | samba | 4.15.13+git.691.3d3cea0641-150300.3.63.1 | SUSE-SU-2023:4096-1 |
| SUSE Manager Proxy 4.2 | samba | 4.15.13+git.691.3d3cea0641-150300.3.63.1 | SUSE-SU-2023:4096-1 |
| SUSE Enterprise Storage 7.1 | samba | 4.15.13+git.691.3d3cea0641-150300.3.63.1 | SUSE-SU-2023:4096-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | samba | 4.19.1+git.312.c912b3d2ef6-1.1 | openSUSE-SU-2024:13332-1 |
| openSUSE Leap 15.5 | samba | 4.17.9+git.421.abde31ca5c2-150500.3.11.1 | SUSE-SU-2023:4046-1 |
| openSUSE Leap 15.4 | samba | 4.15.13+git.691.3d3cea0641-150400.3.31.1 | SUSE-SU-2023:4059-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | samba | 4.18.8-r0 | — |
| Alpine v3.23 | samba | 4.18.8-r0 | — |
| Alpine v3.22 | samba | 4.18.8-r0 | — |
| Alpine v3.21 | samba | 4.18.8-r0 | — |
| Alpine v3.20 | samba | 4.18.8-r0 | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | samba | 4.18.8-r0 | — |
| Alpine v3.18 | samba | 4.18.8-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | samba | No fix yet | — |
| Azure Linux 2 (CBL-Mariner) | samba | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | samba +32 | 4.18.6-101.el9_3 | ELSA-2023-6744 |
| Oracle Linux 8 | ctdb +34 | 4.18.6-2.0.1.el8_9 | ELSA-2023-7467 |
Advisories 18
- ALSA-2023:6744 Moderate: samba security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2023:7467 Moderate: samba security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2023:7464 Red Hat Security Advisory: samba security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2023:7467 Red Hat Security Advisory: samba security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2023:7408 Red Hat Security Advisory: samba security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2023:7371 Red Hat Security Advisory: samba security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2023:6744 Red Hat Security Advisory: samba security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- RHSA-2023:6209 Red Hat Security Advisory: samba security update Red Hat Security Advisories (RHSA) · Jul 28, 2026
- USN-6425-1 samba vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- DSA-5525-1 samba - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2023:4059-1 Security update for samba SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4096-1 Security update for samba SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:13332-1 ctdb-4.19.1+git.312.c912b3d2ef6-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2023:4046-1 Security update for samba SUSE / openSUSE Security Updates · May 2, 2025
- WID-SEC-2023-2620 Samba: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 9, 2025
- NCSC-2025-0026 Kwetsbaarheden verholpen in Oracle JD Edwards NCSC-NL (Netherlands) · Jan 22, 2025
- ELSA-2023-7467 Moderate: samba security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 23, 2023
- ELSA-2023-6744 Moderate: samba security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 16, 2023
References
- RHSA-2023:6209 vendor-advisory
- RHSA-2023:6744 vendor-advisory
- RHSA-2023:7371 vendor-advisory
- RHSA-2023:7408 vendor-advisory
- RHSA-2023:7464 vendor-advisory
- RHSA-2023:7467 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2023-42669 vdb-entry
- RHBZ#2241884 issue-tracking
- https://bugzilla.samba.org/show_bug.cgi?id=15474
- https://www.samba.org/samba/security/CVE-2023-42669.html