CVE-2021-43566

Publication date 11 January 2022

Last updated 24 July 2024

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

2.5 · Low

Score breakdown

All versions of Samba prior to 4.13.16 are vulnerable to a malicious client using an SMB1 or NFS race to allow a directory to be created in an area of the server file system not exported under the share definition. Note that SMB1 has to be enabled, or the share also available via NFS in order for this attack to succeed.

Mitigation

This issue can be mitigated by disabling SMB1, which is the default configuration in Samba 4.11 and above. In environments where SMB1 cannot be disabled, symlink support can be disabled with unix extensions = no.

Status

Package Ubuntu Release Status
samba 24.10 oracular
Fixed 4.13.17~dfsg-0ubuntu1
24.04 LTS noble
Fixed 4.13.17~dfsg-0ubuntu1
23.10 mantic
Fixed 4.13.17~dfsg-0ubuntu1
23.04 lunar
Fixed 4.13.17~dfsg-0ubuntu1
22.10 kinetic
Fixed 4.13.17~dfsg-0ubuntu1
22.04 LTS jammy
Fixed 4.13.17~dfsg-0ubuntu1
21.10 impish
Fixed 2:4.13.17~dfsg-0ubuntu0.21.10.1
21.04 hirsute Ignored end of life
20.04 LTS focal
Fixed 2:4.13.17~dfsg-0ubuntu0.21.04.1
18.04 LTS bionic
Vulnerable
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty Ignored end of ESM support, was needs-triage

Severity score breakdown

Parameter Value
Base score 2.5 · Low
Attack vector Local
Attack complexity High
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact Low
Availability impact None
Vector CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N