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CentOS 6 : samba (CESA-2016:0611) (Badlock)

high Nessus Plugin ID 90449

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Synopsis

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

Description

An update for samba is now available for Red Hat Enterprise Linux 6.

Red Hat Product Security has rated this update as having a security impact of Critical. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

[Updated 13 April 2016] This advisory previously did not list the CVE-2016-2110 issue as addressed by this update. However, this issue did affect samba on Red Hat Enterprise Linux 6, and is addressed by this update. No changes have been made to the packages.

Samba is an open source implementation of the Server Message Block (SMB) protocol and the related Common Internet File System (CIFS) protocol, which allow PC-compatible machines to share files, printers, and various information.

Security Fix(es) :

* Multiple flaws were found in Samba's DCE/RPC protocol implementation. A remote, authenticated attacker could use these flaws to cause a denial of service against the Samba server (high CPU load or a crash) or, possibly, execute arbitrary code with the permissions of the user running Samba (root). This flaw could also be used to downgrade a secure DCE/RPC connection by a man-in-the-middle attacker taking control of an Active Directory (AD) object and compromising the security of a Samba Active Directory Domain Controller (DC).
(CVE-2015-5370)

Note: While Samba packages as shipped in Red Hat Enterprise Linux do not support running Samba as an AD DC, this flaw applies to all roles Samba implements.

* A protocol flaw, publicly referred to as Badlock, was found in the Security Account Manager Remote Protocol (MS-SAMR) and the Local Security Authority (Domain Policy) Remote Protocol (MS-LSAD). Any authenticated DCE/RPC connection that a client initiates against a server could be used by a man-in-the-middle attacker to impersonate the authenticated user against the SAMR or LSA service on the server.
As a result, the attacker would be able to get read/write access to the Security Account Manager database, and use this to reveal all passwords or any other potentially sensitive information in that database. (CVE-2016-2118)

* Several flaws were found in Samba's implementation of NTLMSSP authentication. An unauthenticated, man-in-the-middle attacker could use this flaw to clear the encryption and integrity flags of a connection, causing data to be transmitted in plain text. The attacker could also force the client or server into sending data in plain text even if encryption was explicitly requested for that connection.
(CVE-2016-2110)

* It was discovered that Samba configured as a Domain Controller would establish a secure communication channel with a machine using a spoofed computer name. A remote attacker able to observe network traffic could use this flaw to obtain session-related information about the spoofed machine. (CVE-2016-2111)

* It was found that Samba's LDAP implementation did not enforce integrity protection for LDAP connections. A man-in-the-middle attacker could use this flaw to downgrade LDAP connections to use no integrity protection, allowing them to hijack such connections.
(CVE-2016-2112)

* It was found that Samba did not enable integrity protection for IPC traffic by default. A man-in-the-middle attacker could use this flaw to view and modify the data sent between a Samba server and a client.
(CVE-2016-2115)

Red Hat would like to thank the Samba project for reporting these issues. Upstream acknowledges Jouni Knuutinen (Synopsis) as the original reporter of CVE-2015-5370; and Stefan Metzmacher (SerNet) as the original reporter of CVE-2016-2118, CVE-2016-2110, CVE-2016-2112, and CVE-2016-2115.

Solution

Update the affected samba packages.

See Also

http://www.nessus.org/u?808aa2e9

Plugin Details

Severity: High

ID: 90449

File Name: centos_RHSA-2016-0611.nasl

Version: 2.18

Type: local

Agent: unix

Published: 4/13/2016

Updated: 1/4/2021

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, 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-2016-2118

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: p-cpe:/a:centos:centos:samba-winbind, cpe:/o:centos:centos:6, p-cpe:/a:centos:centos:samba-swat, p-cpe:/a:centos:centos:samba, p-cpe:/a:centos:centos:samba-doc, p-cpe:/a:centos:centos:samba-domainjoin-gui, p-cpe:/a:centos:centos:samba-common, p-cpe:/a:centos:centos:samba-glusterfs, p-cpe:/a:centos:centos:samba-winbind-krb5-locator, p-cpe:/a:centos:centos:samba-winbind-clients, p-cpe:/a:centos:centos:libsmbclient-devel, p-cpe:/a:centos:centos:libsmbclient, p-cpe:/a:centos:centos:samba-winbind-devel, p-cpe:/a:centos:centos:samba-client

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 4/12/2016

Vulnerability Publication Date: 4/12/2016

Reference Information

CVE: CVE-2015-5370, CVE-2016-2110, CVE-2016-2111, CVE-2016-2112, CVE-2016-2115, CVE-2016-2118

RHSA: 2016:0611