Samba 4.x < 4.2.14 / 4.3.x < 4.3.11 / 4.4.x < 4.4.5 SMB2/3 Client Connection Required Signing Downgrade

high Nessus Plugin ID 92466

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Synopsis

The remote Samba server is affected by a signature downgrade vulnerability.

Description

The version of Samba running on the remote host is 4.x prior to 4.2.14, 4.3.x prior to 4.3.11, or 4.4.x prior to 4.4.5. It is, therefore, affected by a flaw in libcli/smb/smbXcli_base.c that is triggered when handling SMB2 and SMB3 client connections. A man-in-the-middle attacker can exploit this, by injecting the SMB2_SESSION_FLAG_IS_GUEST or SMB2_SESSION_FLAG_IS_NULL flags, to downgrade the required signing for a client connection, allowing the attacker to spoof SMB2 and SMB3 servers.

Solution

Upgrade to Samba version 4.2.14 / 4.3.11 / 4.4.5 or later.

Plugin Details

Severity: High

ID: 92466

File Name: samba_4_4_5.nasl

Version: 1.8

Type: remote

Family: Misc.

Published: 7/20/2016

Updated: 11/19/2019

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

Vector: CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2016-2119

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/a:samba:samba

Required KB Items: SMB/NativeLanManager, SMB/samba, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 7/16/2016

Vulnerability Publication Date: 7/7/2016

Reference Information

CVE: CVE-2016-2119

BID: 91700

Detections

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