UBUNTU-CVE-2021-20254

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Source
https://ubuntu.com/security/CVE-2021-20254
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-20254.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2021-20254
Upstream
Downstream
Related
Published
2021-04-29T00:00:00Z
Modified
2025-10-14T16:50:35Z
Severity
  • 6.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A flaw was found in samba. The Samba smbd file server must map Windows group identities (SIDs) into unix group ids (gids). The code that performs this had a flaw that could allow it to read data beyond the end of the array in the case where a negative cache entry had been added to the mapping cache. This could cause the calling code to return those values into the process token that stores the group membership for a user. The highest threat from this vulnerability is to data confidentiality and integrity.

References

Affected packages

Ubuntu:Pro:14.04:LTS / samba

Package

Name
samba
Purl
pkg:deb/ubuntu/samba@2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11?arch=source&distro=trusty/esm

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11

Affected versions

2:3.*

2:3.6.18-1ubuntu3

2:4.*

2:4.0.10+dfsg-4ubuntu2
2:4.0.13+dfsg-1ubuntu1
2:4.1.3+dfsg-2ubuntu2
2:4.1.3+dfsg-2ubuntu3
2:4.1.3+dfsg-2ubuntu4
2:4.1.3+dfsg-2ubuntu5
2:4.1.6+dfsg-1ubuntu1
2:4.1.6+dfsg-1ubuntu2
2:4.1.6+dfsg-1ubuntu2.14.04.1
2:4.1.6+dfsg-1ubuntu2.14.04.2
2:4.1.6+dfsg-1ubuntu2.14.04.3
2:4.1.6+dfsg-1ubuntu2.14.04.4
2:4.1.6+dfsg-1ubuntu2.14.04.5
2:4.1.6+dfsg-1ubuntu2.14.04.7
2:4.1.6+dfsg-1ubuntu2.14.04.8
2:4.1.6+dfsg-1ubuntu2.14.04.9
2:4.1.6+dfsg-1ubuntu2.14.04.11
2:4.1.6+dfsg-1ubuntu2.14.04.12
2:4.1.6+dfsg-1ubuntu2.14.04.13
2:4.3.8+dfsg-0ubuntu0.14.04.2
2:4.3.9+dfsg-0ubuntu0.14.04.1
2:4.3.9+dfsg-0ubuntu0.14.04.3
2:4.3.11+dfsg-0ubuntu0.14.04.1
2:4.3.11+dfsg-0ubuntu0.14.04.2
2:4.3.11+dfsg-0ubuntu0.14.04.3
2:4.3.11+dfsg-0ubuntu0.14.04.4
2:4.3.11+dfsg-0ubuntu0.14.04.6
2:4.3.11+dfsg-0ubuntu0.14.04.7
2:4.3.11+dfsg-0ubuntu0.14.04.8
2:4.3.11+dfsg-0ubuntu0.14.04.9
2:4.3.11+dfsg-0ubuntu0.14.04.10
2:4.3.11+dfsg-0ubuntu0.14.04.11
2:4.3.11+dfsg-0ubuntu0.14.04.12
2:4.3.11+dfsg-0ubuntu0.14.04.13
2:4.3.11+dfsg-0ubuntu0.14.04.14
2:4.3.11+dfsg-0ubuntu0.14.04.16
2:4.3.11+dfsg-0ubuntu0.14.04.17
2:4.3.11+dfsg-0ubuntu0.14.04.19
2:4.3.11+dfsg-0ubuntu0.14.04.20
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm1
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm2
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm3
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm4
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm6
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm7
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm8
2:4.3.11+dfsg-0ubuntu0.14.04.20+esm9

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "libnss-winbind",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libpam-smbpass",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libpam-winbind",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libparse-pidl-perl",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libsmbclient",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libsmbclient-dev",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libsmbsharemodes-dev",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libsmbsharemodes0",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libwbclient-dev",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "libwbclient0",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "python-samba",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "registry-tools",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba-common",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba-common-bin",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba-dev",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba-dsdb-modules",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba-libs",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba-testsuite",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "samba-vfs-modules",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "smbclient",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        },
        {
            "binary_name": "winbind",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.14.04.20+esm11"
        }
    ]
}

Ubuntu:16.04:LTS / samba

Package

Name
samba
Purl
pkg:deb/ubuntu/samba@2:4.3.11+dfsg-0ubuntu0.16.04.34?arch=source&distro=xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2:4.3.11+dfsg-0ubuntu0.16.04.34

Affected versions

2:4.*

2:4.1.17+dfsg-4ubuntu2
2:4.1.20+dfsg-1ubuntu1
2:4.1.20+dfsg-1ubuntu2
2:4.1.20+dfsg-1ubuntu3
2:4.1.20+dfsg-1ubuntu5
2:4.3.3+dfsg-1ubuntu1
2:4.3.3+dfsg-1ubuntu2
2:4.3.3+dfsg-1ubuntu3
2:4.3.6+dfsg-1ubuntu1
2:4.3.8+dfsg-0ubuntu1
2:4.3.9+dfsg-0ubuntu0.16.04.1
2:4.3.9+dfsg-0ubuntu0.16.04.2
2:4.3.9+dfsg-0ubuntu0.16.04.3
2:4.3.11+dfsg-0ubuntu0.16.04.1
2:4.3.11+dfsg-0ubuntu0.16.04.3
2:4.3.11+dfsg-0ubuntu0.16.04.5
2:4.3.11+dfsg-0ubuntu0.16.04.6
2:4.3.11+dfsg-0ubuntu0.16.04.7
2:4.3.11+dfsg-0ubuntu0.16.04.8
2:4.3.11+dfsg-0ubuntu0.16.04.9
2:4.3.11+dfsg-0ubuntu0.16.04.10
2:4.3.11+dfsg-0ubuntu0.16.04.11
2:4.3.11+dfsg-0ubuntu0.16.04.12
2:4.3.11+dfsg-0ubuntu0.16.04.13
2:4.3.11+dfsg-0ubuntu0.16.04.15
2:4.3.11+dfsg-0ubuntu0.16.04.16
2:4.3.11+dfsg-0ubuntu0.16.04.17
2:4.3.11+dfsg-0ubuntu0.16.04.18
2:4.3.11+dfsg-0ubuntu0.16.04.19
2:4.3.11+dfsg-0ubuntu0.16.04.20
2:4.3.11+dfsg-0ubuntu0.16.04.21
2:4.3.11+dfsg-0ubuntu0.16.04.23
2:4.3.11+dfsg-0ubuntu0.16.04.24
2:4.3.11+dfsg-0ubuntu0.16.04.25
2:4.3.11+dfsg-0ubuntu0.16.04.26
2:4.3.11+dfsg-0ubuntu0.16.04.27
2:4.3.11+dfsg-0ubuntu0.16.04.28
2:4.3.11+dfsg-0ubuntu0.16.04.29
2:4.3.11+dfsg-0ubuntu0.16.04.30
2:4.3.11+dfsg-0ubuntu0.16.04.31
2:4.3.11+dfsg-0ubuntu0.16.04.32

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "ctdb",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "libnss-winbind",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "libpam-winbind",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "libparse-pidl-perl",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "libsmbclient",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "libsmbclient-dev",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "libwbclient-dev",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "libwbclient0",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "python-samba",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "registry-tools",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba-common",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba-common-bin",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba-dev",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba-dsdb-modules",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba-libs",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba-testsuite",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "samba-vfs-modules",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "smbclient",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        },
        {
            "binary_name": "winbind",
            "binary_version": "2:4.3.11+dfsg-0ubuntu0.16.04.34"
        }
    ]
}

Ubuntu:18.04:LTS / samba

Package

Name
samba
Purl
pkg:deb/ubuntu/samba@2:4.7.6+dfsg~ubuntu-0ubuntu2.23?arch=source&distro=bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2:4.7.6+dfsg~ubuntu-0ubuntu2.23

Affected versions

2:4.*

2:4.6.7+dfsg-1ubuntu3
2:4.7.1+dfsg-1ubuntu1
2:4.7.3+dfsg-1ubuntu1
2:4.7.4+dfsg-1ubuntu1
2:4.7.6+dfsg~ubuntu-0ubuntu1
2:4.7.6+dfsg~ubuntu-0ubuntu2
2:4.7.6+dfsg~ubuntu-0ubuntu2.2
2:4.7.6+dfsg~ubuntu-0ubuntu2.4
2:4.7.6+dfsg~ubuntu-0ubuntu2.5
2:4.7.6+dfsg~ubuntu-0ubuntu2.6
2:4.7.6+dfsg~ubuntu-0ubuntu2.7
2:4.7.6+dfsg~ubuntu-0ubuntu2.9
2:4.7.6+dfsg~ubuntu-0ubuntu2.10
2:4.7.6+dfsg~ubuntu-0ubuntu2.11
2:4.7.6+dfsg~ubuntu-0ubuntu2.13
2:4.7.6+dfsg~ubuntu-0ubuntu2.14
2:4.7.6+dfsg~ubuntu-0ubuntu2.15
2:4.7.6+dfsg~ubuntu-0ubuntu2.16
2:4.7.6+dfsg~ubuntu-0ubuntu2.17
2:4.7.6+dfsg~ubuntu-0ubuntu2.18
2:4.7.6+dfsg~ubuntu-0ubuntu2.19
2:4.7.6+dfsg~ubuntu-0ubuntu2.20
2:4.7.6+dfsg~ubuntu-0ubuntu2.21

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "ctdb",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "libnss-winbind",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "libpam-winbind",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "libparse-pidl-perl",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "libsmbclient",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "libsmbclient-dev",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "libwbclient-dev",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "libwbclient0",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "python-samba",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "registry-tools",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba-common",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba-common-bin",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba-dev",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba-dsdb-modules",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba-libs",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba-testsuite",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "samba-vfs-modules",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "smbclient",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        },
        {
            "binary_name": "winbind",
            "binary_version": "2:4.7.6+dfsg~ubuntu-0ubuntu2.23"
        }
    ]
}

Ubuntu:20.04:LTS / samba

Package

Name
samba
Purl
pkg:deb/ubuntu/samba@2:4.11.6+dfsg-0ubuntu1.8?arch=source&distro=focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2:4.11.6+dfsg-0ubuntu1.8

Affected versions

2:4.*

2:4.10.7+dfsg-0ubuntu2
2:4.10.7+dfsg-0ubuntu3
2:4.11.1+dfsg-3ubuntu1
2:4.11.1+dfsg-3ubuntu2
2:4.11.1+dfsg-3ubuntu4
2:4.11.5+dfsg-1ubuntu1
2:4.11.5+dfsg-1ubuntu2
2:4.11.6+dfsg-0ubuntu1
2:4.11.6+dfsg-0ubuntu1.1
2:4.11.6+dfsg-0ubuntu1.2
2:4.11.6+dfsg-0ubuntu1.3
2:4.11.6+dfsg-0ubuntu1.4
2:4.11.6+dfsg-0ubuntu1.5
2:4.11.6+dfsg-0ubuntu1.6

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "ctdb",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "libnss-winbind",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "libpam-winbind",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "libsmbclient",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "libsmbclient-dev",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "libwbclient-dev",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "libwbclient0",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "python3-samba",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "registry-tools",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba-common",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba-common-bin",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba-dev",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba-dsdb-modules",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba-libs",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba-testsuite",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "samba-vfs-modules",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "smbclient",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        },
        {
            "binary_name": "winbind",
            "binary_version": "2:4.11.6+dfsg-0ubuntu1.8"
        }
    ]
}