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Full vulnerability report · 2023
CVE-2023-4091High confidence

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

Red Hat · Red Hat Enterprise Linux 8

6.5MediumCVSS 3.1
Recommended action
Scheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
Distribution package intelligence

Ubuntu vendor package status

Canonical’s release and source-package findings are shown separately from local repository availability.

1 package state
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Ubuntu releaseSource packageVendor stateFixed versionEvidence
Ubuntu 24.04 LTSnoble · standard archivesambaVendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree.2:4.18.6+dfsg-1ubuntu2.1Canonical record ↗Source updated 4 Sept 2026
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2023-53981

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled

Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.

Patch available
01

What, why and how

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.

What

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.

Why

During installation, installed file permissions are set to allow anyone to modify those files.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

During installation, installed file permissions are set to allow anyone to modify those files.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Incorrect Default Permissions → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-276

CWE-276: Incorrect Default Permissions. During installation, installed file permissions are set to allow anyone to modify those files.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkCWE-276
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-W-2023-2620Samba: Mehrere Schwachstellen

Ein entfernter anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Samba ausnutzen, um einen Denial-of-Service-Zustand zu erzeugen, Dateien zu manipulieren oder vertrauliche Informationen offenzulegen.

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0969Multiples vulnérabilités dans les produits VMware

ERecord?id=CVE-2023-39593 Référence CVE CVE-2023-39615 https://www.cve.org/CVERecord?id=CVE-2023-39615 Référence CVE CVE-2023-3978 https://www.cve.org/CVERecord?id=CVE-2023-3978 Référence CVE CVE-2023-39978 https://www.cve.org/CVERecord?id=CVE-2023-39978 Référence CVE CVE-2023-4016 https://www.cve.org/CVERecord?id=CVE-2023-4016 Référence CVE CVE-2023-40217 https://www.cve.org/CVERecord?id=CVE-2023-40217 Référence CVE CVE-2023-4039 https://www.cve.org/CVERecord?id=CVE-2023-4039 Référence CVE CVE-2023-40403 https://www.cve.org/CVERecord?id=CVE-2023-40403 Référence CVE CVE-2023-40745 https://www.cve.org/CVERecord?id=CVE-2023-40745 Référence CVE CVE-2023-4091 https://www.cve.org/CVERecord?id=CVE-2023-4091 Référence CVE CVE-2023-41175 https://www.cve.org/CVERecord?id=CVE-2023-41175 Référence CVE CVE-2023-4154 https://www.cve.org/CVERecord?id=CVE-2023-4154 Référence CVE CVE-2023-42669 https://www.cve.org/CVERecord?id=CVE-2023-42669 Référence CVE CVE-2023-42670 https://www.cve.org/CVERecord?id=CVE-2023-42670 Référence CVE CVE-2023-43887 https://www.cve.org/CVERecord?id=CVE-2023-43887 Référence CVE CVE-2023-44487 https://www.cve.org/CVERecord?id=CVE-2023-44487 Référence CVE CVE-2023-4527 https://www.cve.org/CVERecord?id=CVE-2023-4527 Référence CVE CVE-2023-45283 https://www.cve.org/CVERecord?id=CVE-2

Official advisory
CERT-FR · French · CERTFR-2025-AVI-0309Multiples vulnérabilités dans les produits IBM

/CVERecord?id=CVE-2023-1076 Référence CVE CVE-2023-1409 https://www.cve.org/CVERecord?id=CVE-2023-1409 Référence CVE CVE-2023-23931 https://www.cve.org/CVERecord?id=CVE-2023-23931 Référence CVE CVE-2023-23934 https://www.cve.org/CVERecord?id=CVE-2023-23934 Référence CVE CVE-2023-25577 https://www.cve.org/CVERecord?id=CVE-2023-25577 Référence CVE CVE-2023-2650 https://www.cve.org/CVERecord?id=CVE-2023-2650 Référence CVE CVE-2023-3446 https://www.cve.org/CVERecord?id=CVE-2023-3446 Référence CVE CVE-2023-38325 https://www.cve.org/CVERecord?id=CVE-2023-38325 Référence CVE CVE-2023-3961 https://www.cve.org/CVERecord?id=CVE-2023-3961 Référence CVE CVE-2023-4091 https://www.cve.org/CVERecord?id=CVE-2023-4091 Référence CVE CVE-2023-42669 https://www.cve.org/CVERecord?id=CVE-2023-42669 Référence CVE CVE-2023-46136 https://www.cve.org/CVERecord?id=CVE-2023-46136 Référence CVE CVE-2023-4807 https://www.cve.org/CVERecord?id=CVE-2023-4807 Référence CVE CVE-2023-49083 https://www.cve.org/CVERecord?id=CVE-2023-49083 Référence CVE CVE-2023-50782 https://www.cve.org/CVERecord?id=CVE-2023-50782 Référence CVE CVE-2023-52434 https://www.cve.org/CVERecord?id=CVE-2023-52434 Référence CVE CVE-2023-52439 https://www.cve.org/CVERecord?id=CVE-2023-52439 Référence CVE CVE-2023-52448 https://www.cve.org/CVERecord?id=CVE

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0506Multiples vulnérabilités dans Juniper Secure Analytics

d?id=CVE-2023-39198 Référence CVE CVE-2023-39615 https://www.cve.org/CVERecord?id=CVE-2023-39615 Référence CVE CVE-2023-40283 https://www.cve.org/CVERecord?id=CVE-2023-40283 Référence CVE CVE-2023-40546 https://www.cve.org/CVERecord?id=CVE-2023-40546 Référence CVE CVE-2023-40547 https://www.cve.org/CVERecord?id=CVE-2023-40547 Référence CVE CVE-2023-40548 https://www.cve.org/CVERecord?id=CVE-2023-40548 Référence CVE CVE-2023-40549 https://www.cve.org/CVERecord?id=CVE-2023-40549 Référence CVE CVE-2023-40550 https://www.cve.org/CVERecord?id=CVE-2023-40550 Référence CVE CVE-2023-40551 https://www.cve.org/CVERecord?id=CVE-2023-40551 Référence CVE CVE-2023-4091 https://www.cve.org/CVERecord?id=CVE-2023-4091 Référence CVE CVE-2023-4128 https://www.cve.org/CVERecord?id=CVE-2023-4128 Référence CVE CVE-2023-4132 https://www.cve.org/CVERecord?id=CVE-2023-4132 Référence CVE CVE-2023-4133 https://www.cve.org/CVERecord?id=CVE-2023-4133 Référence CVE CVE-2023-4155 https://www.cve.org/CVERecord?id=CVE-2023-4155 Référence CVE CVE-2023-4206 https://www.cve.org/CVERecord?id=CVE-2023-4206 Référence CVE CVE-2023-4207 https://www.cve.org/CVERecord?id=CVE-2023-4207 Référence CVE CVE-2023-4208 https://www.cve.org/CVERecord?id=CVE-2023-4208 Référence CVE CVE-2023-4244 https://www.cve.org/CVERecord?id=CVE-2023-4244 Ré

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0423Multiples vulnérabilités dans les produits NetApp

De multiples vulnérabilités ont été découvertes dans les produits NetApp. Elles permettent à un attaquant de provoquer un déni de service à distance, une atteinte à la confidentialité des données, une atteinte à l'intégrité des données.

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0305Multiples vulnérabilités dans les produits IBM

ord?id=CVE-2023-32681 Référence CVE CVE-2023-3341 https://www.cve.org/CVERecord?id=CVE-2023-3341 Référence CVE CVE-2023-33850 https://www.cve.org/CVERecord?id=CVE-2023-33850 Référence CVE CVE-2023-34966 https://www.cve.org/CVERecord?id=CVE-2023-34966 Référence CVE CVE-2023-34967 https://www.cve.org/CVERecord?id=CVE-2023-34967 Référence CVE CVE-2023-34968 https://www.cve.org/CVERecord?id=CVE-2023-34968 Référence CVE CVE-2023-37920 https://www.cve.org/CVERecord?id=CVE-2023-37920 Référence CVE CVE-2023-38546 https://www.cve.org/CVERecord?id=CVE-2023-38546 Référence CVE CVE-2023-39615 https://www.cve.org/CVERecord?id=CVE-2023-39615 Référence CVE CVE-2023-4091 https://www.cve.org/CVERecord?id=CVE-2023-4091 Référence CVE CVE-2023-42465 https://www.cve.org/CVERecord?id=CVE-2023-42465 Référence CVE CVE-2023-42669 https://www.cve.org/CVERecord?id=CVE-2023-42669 Référence CVE CVE-2023-42794 https://www.cve.org/CVERecord?id=CVE-2023-42794 Référence CVE CVE-2023-42795 https://www.cve.org/CVERecord?id=CVE-2023-42795 Référence CVE CVE-2023-43642 https://www.cve.org/CVERecord?id=CVE-2023-43642 Référence CVE CVE-2023-43804 https://www.cve.org/CVERecord?id=CVE-2023-43804 Référence CVE CVE-2023-45648 https://www.cve.org/CVERecord?id=CVE-2023-45648 Référence CVE CVE-2023-45803 https://www.cve.org/CVERecord?id=C

Official advisory
CERT-FR · French · CERTFR-2024-AVI-0262Multiples vulnérabilités dans les produits IBM

ERecord?id=CVE-2023-23931 Référence CVE CVE-2023-27043 https://www.cve.org/CVERecord?id=CVE-2023-27043 Référence CVE CVE-2023-3446 https://www.cve.org/CVERecord?id=CVE-2023-3446 Référence CVE CVE-2023-34966 https://www.cve.org/CVERecord?id=CVE-2023-34966 Référence CVE CVE-2023-34967 https://www.cve.org/CVERecord?id=CVE-2023-34967 Référence CVE CVE-2023-34968 https://www.cve.org/CVERecord?id=CVE-2023-34968 Référence CVE CVE-2023-36632 https://www.cve.org/CVERecord?id=CVE-2023-36632 Référence CVE CVE-2023-3817 https://www.cve.org/CVERecord?id=CVE-2023-3817 Référence CVE CVE-2023-3961 https://www.cve.org/CVERecord?id=CVE-2023-3961 Référence CVE CVE-2023-4091 https://www.cve.org/CVERecord?id=CVE-2023-4091 Référence CVE CVE-2023-42503 https://www.cve.org/CVERecord?id=CVE-2023-42503 Référence CVE CVE-2023-42669 https://www.cve.org/CVERecord?id=CVE-2023-42669 Référence CVE CVE-2023-42753 https://www.cve.org/CVERecord?id=CVE-2023-42753 Référence CVE CVE-2023-4806 https://www.cve.org/CVERecord?id=CVE-2023-4806 Référence CVE CVE-2023-4813 https://www.cve.org/CVERecord?id=CVE-2023-4813 Référence CVE CVE-2023-50960 https://www.cve.org/CVERecord?id=CVE-2023-50960 Référence CVE CVE-2023-50961 https://www.cve.org/CVERecord?id=CVE-2023-50961 Référence CVE CVE-2023-5678 https://www.cve.org/CVERecord?id=CVE-20

Official advisory
CERT-FR · French · CERTFR-2023-AVI-1011Multiples vulnérabilités dans les produits Qnap

De multiples vulnérabilités ont été découvertes dans les produits Qnap . Elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, une exécution de code arbitraire et une injection de code indirecte à distance (XSS).

Official advisory
CERT-FR · French · CERTFR-2023-AVI-0831Multiples vulnérabilités dans Samba

De multiples vulnérabilités ont été découvertes dans Samba . Elles permettent à un attaquant de provoquer un déni de service à distance, un contournement de la politique de sécurité et une atteinte à la confidentialité des données.

Official advisory
NCSC-NL · Dutch · NCSC-2025-0026Kwetsbaarheden verholpen in Oracle JD Edwards

De kwetsbaarheden in Oracle JD Edwards EnterpriseOne Tools stellen ongeauthenticeerde kwaadwillenden in staat om het systeem te compromitteren via HTTP-verzoeken. Dit kan leiden tot ongeautoriseerde toegang tot kritieke gegevens en gegevenswijzigingen.

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
See the vendor and CVE records for the affected range.
Fixed
0:4.18.6-2.el8_9 < *; 0:4.15.5-13.el8_6 < *; 0:4.17.5-4.el8_8 < *; 0:4.18.6-101.el9_3 < *; 0:4.15.5-111.el9_0 < *; 0:4.17.5-104.el9_2 < *
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 3 Nov 2023 · Last source change 20 Nov 2025, 18:27 UTC · CWE-276 · Incorrect Default Permissions

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2023-53981
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD modified after enrichment

Missing structured fields: affected versions. Missing data is not evidence of low risk; review the primary advisory.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2023-4091 · cve.blacktree.nl