libcli/smb/smbXcli_base.c in Samba 4.x before 4.2.14, 4.3.x before 4.3.11, and 4.4.x before 4.4.5 allows man-in-the-middle attackers to bypass a client-signing protection mechanism, and consequently spoof SMB2 and SMB3 servers, via the (1) SMB2_SESSION_FLAG_IS_GUEST or (2) SMB2_SESSION_FLAG_IS_NULL flag.
https://www.samba.org/samba/security/CVE-2016-2119.html
http://www.oracle.com/technetwork/topics/security/linuxbulletinjul2016-3090544.html
http://rhn.redhat.com/errata/RHSA-2016-1487.html
http://rhn.redhat.com/errata/RHSA-2016-1486.html
http://rhn.redhat.com/errata/RHSA-2016-1494.html
http://lists.opensuse.org/opensuse-updates/2016-07/msg00060.html
http://www.securityfocus.com/bid/91700
Source: MITRE
Published: 2016-07-07
Updated: 2022-08-29
Type: CWE-94
Base Score: 6.8
Vector: AV:N/AC:M/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 1.6
Severity: HIGH