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Amazon Linux AMI : samba (ALAS-2016-686) (Badlock)

high Nessus Plugin ID 90514

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Synopsis

The remote Amazon Linux AMI host is missing a security update.

Description

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)

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 validate SSL/TLS certificates in certain connections. A man-in-the-middle attacker could use this flaw to spoof a Samba server using a specially crafted SSL/TLS certificate.
(CVE-2016-2113)

It was discovered that Samba did not enforce Server Message Block (SMB) signing for clients using the SMB1 protocol. A man-in-the-middle attacker could use this flaw to modify traffic between a client and a server. (CVE-2016-2114)

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)

Solution

Run 'yum update samba' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2016-686.html

Plugin Details

Severity: High

ID: 90514

File Name: ala_ALAS-2016-686.nasl

Version: 2.11

Type: local

Agent: unix

Published: 4/14/2016

Updated: 7/10/2019

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

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

CVSS v3

Risk Factor: High

Base Score: 7.5

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:libsmbclient, p-cpe:/a:amazon:linux:samba, p-cpe:/a:amazon:linux:samba-pidl, p-cpe:/a:amazon:linux:libwbclient, p-cpe:/a:amazon:linux:samba-common-libs, p-cpe:/a:amazon:linux:samba-libs, p-cpe:/a:amazon:linux:samba-winbind-krb5-locator, p-cpe:/a:amazon:linux:samba-test-devel, p-cpe:/a:amazon:linux:samba-python, p-cpe:/a:amazon:linux:ctdb-tests, cpe:/o:amazon:linux, p-cpe:/a:amazon:linux:samba-test, p-cpe:/a:amazon:linux:samba-client-libs, p-cpe:/a:amazon:linux:ctdb, p-cpe:/a:amazon:linux:samba-test-libs, p-cpe:/a:amazon:linux:libwbclient-devel, p-cpe:/a:amazon:linux:samba-winbind-clients, p-cpe:/a:amazon:linux:samba-winbind, p-cpe:/a:amazon:linux:samba-debuginfo, p-cpe:/a:amazon:linux:samba-client, p-cpe:/a:amazon:linux:samba-common-tools, p-cpe:/a:amazon:linux:samba-devel, p-cpe:/a:amazon:linux:samba-common, p-cpe:/a:amazon:linux:libsmbclient-devel, p-cpe:/a:amazon:linux:ctdb-devel, p-cpe:/a:amazon:linux:samba-winbind-modules

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

Patch Publication Date: 4/13/2016

Vulnerability Publication Date: 4/12/2016

Reference Information

CVE: CVE-2015-5370, CVE-2016-2110, CVE-2016-2111, CVE-2016-2112, CVE-2016-2113, CVE-2016-2114, CVE-2016-2115, CVE-2016-2118

ALAS: 2016-686