CVE-2023-4091

Severity
6.5MEDIUM
EPSS
0.5%
top 35.12%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedNov 3

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 per

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:NExploitability: 2.8 | Impact: 3.6

Affected Packages4 packages

NVDsamba/samba4.18.04.18.8+2
Debiansamba< 2:4.13.13+dfsg-1~deb11u6+3
Ubuntusamba< 2:4.15.13+dfsg-0ubuntu0.20.04.6+2

Also affects: Fedora 39, Enterprise Linux 8.0, 9.0

🔴Vulnerability Details

6
CVEList
Samba: smb clients can truncate files with read-only permissions2023-11-03
GHSA
GHSA-f6jj-3gjw-frjm: A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with read-only permissions when the Samba VFS modul2023-11-03
OSV
CVE-2023-4091: A vulnerability was discovered in Samba, where the flaw allows SMB clients to truncate files, even with read-only permissions when the Samba VFS modul2023-11-03
OSV
samba vulnerabilities2023-10-17
OSV
samba regression2023-10-11

📋Vendor Advisories

4
Ubuntu
Samba vulnerabilities2023-10-17
Red Hat
samba: SMB clients can truncate files with read-only permissions2023-10-10
Ubuntu
Samba vulnerabilities2023-10-10
Debian
CVE-2023-4091: samba - A vulnerability was discovered in Samba, where the flaw allows SMB clients to tr...2023