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6.5 Medium

CVE-2023-4091 Samba: smb clients can truncate files with read-only permissions

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.

CVSS 3.1 detail

Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Exploitable remotely over the network, with an ordinary account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector
Network
Attack complexity
Low
Privileges required
Low
Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

Affected products and versions

Product Affected versions Fixed in
Red Hat Enterprise Linux 8 Versions not published
Red Hat Enterprise Linux 8.6 Extended Update Support Versions not published
Red Hat Enterprise Linux 8.8 Extended Update Support Versions not published
Red Hat Enterprise Linux 9 Versions not published
Red Hat Enterprise Linux 9.0 Extended Update Support Versions not published
Red Hat Enterprise Linux 9.2 Extended Update Support Versions not published
Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 Versions not published
Red Hat Enterprise Linux 6 Versions not published
Red Hat Enterprise Linux 7 Versions not published
Show the other branch
Product Affected versions Fixed in
Red Hat Storage 3 Versions not published

Other CVEs of Red Hat Enterprise Linux 8

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CVE-2026-123876 Podman: containers-common: containers-common: default seccomp af_vsock/netlink_audit deny rules bypassable via 32-bit truncation 4.4 Medium CVE-2026-120749 Dbus: dbus-daemon: dbus-daemon aborts (reply_serial != 0) when a broadcast from the driver cannot be delivered to a monitored bus 6.2 Medium CVE-2026-123037 Ansible-core: user module generate_ssh_key follows a symlinked ~/.ssh enabling local privilege escalation (incomplete fix of cve-2024-9902) 6.7 Medium CVE-2026-123151 Gdb: gdb: stack buffer overflow in parse_tsv_definition via stale rs->buf tail Not rated
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