CVE-2023-4091

Published: Nov 3, 2023

Modified: Nov 20, 2025

PUBLISHED

CVSS v3.1

6.5

MEDIUM

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.

Vendor	Product	Versions
Red Hat	Red Hat Enterprise Linux 8	unaffected `0:4.18.6-2.el8_9 - < *`
Red Hat	Red Hat Enterprise Linux 8	unaffected `0:4.18.6-2.el8_9 - < *`
Red Hat	Red Hat Enterprise Linux 8.6 Extended Update Support	unaffected `0:4.15.5-13.el8_6 - < *`
Red Hat	Red Hat Enterprise Linux 8.8 Extended Update Support	unaffected `0:4.17.5-4.el8_8 - < *`
Red Hat	Red Hat Enterprise Linux 9	unaffected `0:4.18.6-101.el9_3 - < *`
Red Hat	Red Hat Enterprise Linux 9	unaffected `0:4.18.6-101.el9_3 - < *`
Red Hat	Red Hat Enterprise Linux 9.0 Extended Update Support	unaffected `0:4.15.5-111.el9_0 - < *`
Red Hat	Red Hat Enterprise Linux 9.2 Extended Update Support	unaffected `0:4.17.5-104.el9_2 - < *`
Red Hat	Red Hat Virtualization 4 for Red Hat Enterprise Linux 8	unaffected `0:4.15.5-13.el8_6 - < *`
Red Hat	Red Hat Enterprise Linux 6	All versions
Red Hat	Red Hat Enterprise Linux 6	All versions
Red Hat	Red Hat Enterprise Linux 7	All versions
Red Hat	Red Hat Storage 3	All versions