Riskcovery

CVE-2023-4091

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

State
Published
Severity
6.5 Medium
Published
Nov 3, 2023
Updated
Nov 20, 2025
Reserved
Aug 2, 2023

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.16.5 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Nredhat

Weaknesses

  • CWE-276 Incorrect Default Permissions

Affected Products

ProductVersions
Red Hat Enterprise Linux 8Red Hat
  • 0:4.18.6-2.el8_9 and laterNot affected
Red Hat Enterprise Linux 8Red Hat
  • 0:4.18.6-2.el8_9 and laterNot affected
Red Hat Enterprise Linux 8.6 Extended Update SupportRed Hat
  • 0:4.15.5-13.el8_6 and laterNot affected
Red Hat Enterprise Linux 8.8 Extended Update SupportRed Hat
  • 0:4.17.5-4.el8_8 and laterNot affected
Red Hat Enterprise Linux 9Red Hat
  • 0:4.18.6-101.el9_3 and laterNot affected
Red Hat Enterprise Linux 9Red Hat
  • 0:4.18.6-101.el9_3 and laterNot affected
Red Hat Enterprise Linux 9.0 Extended Update SupportRed Hat
  • 0:4.15.5-111.el9_0 and laterNot affected
Red Hat Enterprise Linux 9.2 Extended Update SupportRed Hat
  • 0:4.17.5-104.el9_2 and laterNot affected
Red Hat Virtualization 4 for Red Hat Enterprise Linux 8Red Hat
  • 0:4.15.5-13.el8_6 and laterNot affected
Red Hat Enterprise Linux 6Red Hat
    Red Hat Enterprise Linux 6Red Hat
      Red Hat Enterprise Linux 7Red Hat
        Red Hat Storage 3Red Hat

          References

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