Vulnerability · Published Nov 3, 2023 · Assigned by redhat
CVE-2023-4091Samba: smb clients can truncate files with read-only permissions
Medium 6.5
In plain English
A medium-severity incorrect default permissions in Red Hat Enterprise Linux 6 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 71% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)1.3%top 28.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with read-only permissions when the Samba VFS module "acl_xattr" is configured with "acl_xattr:ignore system acls = yes". The SMB protocol allows opening files when the client requests read-only access but then implicitly truncates the opened file to 0 bytes if the client specifies a separate OVERWRITE create disposition request. The issue arises in configurations that bypass kernel file system permissions checks, relying solely on Samba's permissions.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | ctdb | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | ctdb | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | libnetapi | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | libnetapi | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | libnetapi-devel | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | libnetapi-devel | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | libsmbclient | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | libsmbclient | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | libsmbclient-devel | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | libsmbclient-devel | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | libwbclient | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | libwbclient | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | libwbclient-devel | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | libwbclient-devel | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | python3-samba | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | python3-samba | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | python3-samba-dc | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | python3-samba-dc | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | python3-samba-devel | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | python3-samba-devel | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | python3-samba-test | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | python3-samba-test | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-client | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-client | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-client-libs | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-client-libs | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-common | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-common | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-common-libs | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-common-libs | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-common-tools | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-common-tools | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-dc-libs | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-dc-libs | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-dcerpc | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-dcerpc | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-devel | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-devel | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-krb5-printing | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-krb5-printing | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-ldb-ldap-modules | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-ldb-ldap-modules | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-libs | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-libs | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-pidl | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-pidl | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-test | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-test | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-test-libs | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-test-libs | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-tools | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-tools | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-usershares | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-usershares | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-vfs-iouring | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-vfs-iouring | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-winbind | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-winbind | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-winbind-clients | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-winbind-clients | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-winbind-krb5-locator | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-winbind-krb5-locator | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-winbind-modules | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-winbind-modules | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| AlmaLinux:8 | samba-winexe | 4.18.6-2.el8_9.alma.1 | ALSA-2023:7467 |
| AlmaLinux:9 | samba-winexe | 4.18.6-101.el9_3.alma.1 | ALSA-2023:6744 |
| Alpine:v3.20 | samba | 4.18.8-r0 | ALPINE-CVE-2023-4091 |
| Alpine:v3.21 | samba | 4.18.8-r0 | ALPINE-CVE-2023-4091 |
| Alpine:v3.22 | samba | 4.18.8-r0 | ALPINE-CVE-2023-4091 |
| Alpine:v3.23 | samba | 4.18.8-r0 | ALPINE-CVE-2023-4091 |
| Alpine:v3.24 | samba | 4.18.8-r0 | ALPINE-CVE-2023-4091 |
| Debian:12 | samba | 2:4.17.12+dfsg-0+deb12u1 | DSA-5525-1 |
| Debian:12 | samba | 2:4.17.12+dfsg-0+deb12u1 | DEBIAN-CVE-2023-4091 |
| Debian:13 | samba | 2:4.19.1+dfsg-1 | DEBIAN-CVE-2023-4091 |
| Debian:14 | samba | 2:4.19.1+dfsg-1 | DEBIAN-CVE-2023-4091 |
| Ubuntu:22.04:LTS | samba | 2:4.15.13+dfsg-0ubuntu1.5 | USN-6425-1 |
| Ubuntu:22.04:LTS | samba | 2:4.15.13+dfsg-0ubuntu1.5 | UBUNTU-CVE-2023-4091 |
| Ubuntu:24.04:LTS | samba | 2:4.18.6+dfsg-1ubuntu2.1 | UBUNTU-CVE-2023-4091 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support | see references |
| Red Hat | Red Hat Enterprise Linux 8.8 Extended Update Support | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat Enterprise Linux 9.0 Extended Update Support | see references |
| Red Hat | Red Hat Enterprise Linux 9.2 Extended Update Support | see references |
| Red Hat | Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Storage 3 | see references |
Weakness: CWE-276 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
References
- RHSA-2023:6209 vendor-advisory, x_refsource_REDHAT
- RHSA-2023:6744 vendor-advisory, x_refsource_REDHAT
- RHSA-2023:7371 vendor-advisory, x_refsource_REDHAT
- RHSA-2023:7408 vendor-advisory, x_refsource_REDHAT
- RHSA-2023:7464 vendor-advisory, x_refsource_REDHAT
- RHSA-2023:7467 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2023-4091 vdb-entry, x_refsource_REDHAT
- RHBZ#2241882 issue-tracking, x_refsource_REDHAT
- https://bugzilla.samba.org/show_bug.cgi?id=15439
- https://www.samba.org/samba/security/CVE-2023-4091.html
- https://lists.debian.org/debian-lts-announce/2024/04/msg00015.html x_transferred
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZUMVALLFFDFC53JZMUWA6HPD7HUGAP5I/ x_transferred
- https://security.netapp.com/advisory/ntap-20231124-0002/ x_transferred