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Ubuntu 20.04 LTS : Samba vulnerabilities (USN-5142-1)

high Nessus Plugin ID 155297

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Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 20.04 LTS / 21.04 / 21.10 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5142-1 advisory.

 - A flaw was found in the way Samba, as an Active Directory Domain Controller, implemented Kerberos name- based authentication. The Samba AD DC, could become confused about the user a ticket represents if it did not strictly require a Kerberos PAC and always use the SIDs found within. The result could include total domain compromise. (CVE-2020-25719)

 - A flaw was found in the way samba implemented SMB1 authentication. An attacker could use this flaw to retrieve the plaintext password sent over the wire even if Kerberos authentication was required.
 (CVE-2016-2124)

 - A flaw was found in the way Samba maps domain users to local users. An authenticated attacker could use this flaw to cause possible privilege escalation. (CVE-2020-25717)

 - A flaw was found in the way samba, as an Active Directory Domain Controller, is able to support an RODC (read-only domain controller). This would allow an RODC to print administrator tickets. (CVE-2020-25718)

 - Kerberos acceptors need easy access to stable AD identifiers (eg objectSid). Samba as an AD DC now provides a way for Linux applications to obtain a reliable SID (and samAccountName) in issued tickets.
 (CVE-2020-25721)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-5142-1

Plugin Details

Severity: High

ID: 155297

File Name: ubuntu_USN-5142-1.nasl

Version: 1.12

Type: local

Agent: unix

Published: 11/12/2021

Updated: 10/20/2023

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 6.7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2020-25719

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS Score Source: CVE-2021-3738

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:ctdb, p-cpe:/a:canonical:ubuntu_linux:libnss-winbind, p-cpe:/a:canonical:ubuntu_linux:libpam-winbind, p-cpe:/a:canonical:ubuntu_linux:libsmbclient, p-cpe:/a:canonical:ubuntu_linux:libsmbclient-dev, p-cpe:/a:canonical:ubuntu_linux:libwbclient-dev, p-cpe:/a:canonical:ubuntu_linux:libwbclient0, p-cpe:/a:canonical:ubuntu_linux:python3-samba, p-cpe:/a:canonical:ubuntu_linux:registry-tools, p-cpe:/a:canonical:ubuntu_linux:samba, p-cpe:/a:canonical:ubuntu_linux:samba-common, p-cpe:/a:canonical:ubuntu_linux:samba-common-bin, p-cpe:/a:canonical:ubuntu_linux:samba-dev, p-cpe:/a:canonical:ubuntu_linux:samba-dsdb-modules, p-cpe:/a:canonical:ubuntu_linux:samba-libs, p-cpe:/a:canonical:ubuntu_linux:samba-testsuite, p-cpe:/a:canonical:ubuntu_linux:samba-vfs-modules, p-cpe:/a:canonical:ubuntu_linux:smbclient, p-cpe:/a:canonical:ubuntu_linux:winbind

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Ease: No known exploits are available

Patch Publication Date: 11/11/2021

Vulnerability Publication Date: 10/12/2021

Reference Information

CVE: CVE-2016-2124, CVE-2020-25717, CVE-2020-25718, CVE-2020-25719, CVE-2020-25721, CVE-2020-25722, CVE-2021-23192, CVE-2021-3671, CVE-2021-3738

IAVA: 2021-A-0554-S

USN: 5142-1