CVE-2023-4091
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data tampering.
- Exploit odds
- 1.3% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 1.3% in the next 30 days (EPSS).
- Severity: 6.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 1.3% · EPSS, next 30 days
- Weakness
- CWE-276 · Incorrect default permissions
- Record status
- Modified
Affected
- Samba < 4.17.12
- Samba < 4.18.8
- Samba < 4.19.1
- Fedoraproject Fedora 39
- Redhat Storage 3.0
- Redhat Enterprise Linux 8.0
- Redhat Enterprise Linux Eus 9.0
Attack profile CVSS 3.1 · 6.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2023-4091.md and follow it. Check whether this project is affected by CVE-2023-4091. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://www.samba.org/samba/security/CVE-2023-4091.html
- https://www.samba.org/samba/security/CVE-2023-4091.html
References
- https://access.redhat.com/errata/RHSA-2023:6209
- https://access.redhat.com/errata/RHSA-2023:6744
- https://access.redhat.com/errata/RHSA-2023:7371
- https://access.redhat.com/errata/RHSA-2023:7408
- https://access.redhat.com/errata/RHSA-2023:7464
- https://access.redhat.com/errata/RHSA-2023:7467
- https://access.redhat.com/security/cve/CVE-2023-4091
- https://bugzilla.redhat.com/show_bug.cgi?id=2241882
- https://bugzilla.samba.org/show_bug.cgi?id=15439
- https://www.samba.org/samba/security/CVE-2023-4091.html
- https://access.redhat.com/errata/RHSA-2023:6209
- https://access.redhat.com/errata/RHSA-2023:6744
- https://access.redhat.com/errata/RHSA-2023:7371
- https://access.redhat.com/errata/RHSA-2023:7408
- https://access.redhat.com/errata/RHSA-2023:7464
- https://access.redhat.com/errata/RHSA-2023:7467
- https://access.redhat.com/security/cve/CVE-2023-4091
- https://bugzilla.redhat.com/show_bug.cgi?id=2241882
- https://bugzilla.samba.org/show_bug.cgi?id=15439
- https://lists.debian.org/debian-lts-announce/2024/04/msg00015.html
- https://lists.fedoraproject.org/archives/list/[email protected]/message/ZUMVALLFFDFC53JZMUWA6HPD7HUGAP5I/
- https://security.netapp.com/advisory/ntap-20231124-0002/
- https://www.samba.org/samba/security/CVE-2023-4091.html