Samba from version 4.7.0 has a vulnerability that allows a user in a Samba AD domain to crash the KDC when Samba is built in the non-default MIT Kerberos configuration. With this advisory the Samba Team clarify that the MIT Kerberos build of the Samba AD DC is considered experimental. Therefore the Samba Team will not issue security patches for this configuration. Additionally, Samba 4.7.12, 4.8.7 and 4.9.3 have been issued as security releases to prevent building of the AD DC with MIT Kerberos unless --with-experimental-mit-ad-dc is specified to the configure command.

The remote host is affected by the vulnerability described in GLSA-202003-52 (Samba: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Samba. Please review       the CVE identifiers referenced below for details.
  Impact :

    A remote attacker could possibly execute arbitrary code, cause a Denial       of Service condition, conduct a man-in-the-middle attack, or obtain       sensitive information.
  Workaround :

    There is no known workaround at this time.

Update to Samba 4.9.3

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Update to Samba 4.8.7

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for samba fixes the following issues :

Update to samba version 4.7.11.

Security issues fixed :

CVE-2018-14629: Fixed CNAME loops in Samba AD DC DNS server (bsc#1116319).

CVE-2018-16841: Fixed segfault on PKINIT when mis-matching principal (bsc#1116320).

CVE-2018-16851: Fixed NULL pointer de-reference in Samba AD DC LDAP server (bsc#1116322).

CVE-2018-16853: Mark MIT support for the AD DC experimental (bsc#1116324).

Non-security issues fixed: Fixed do not take over stderr when there is no log file (bsc#1101499).

Fixed ctdb_mutex_ceph_rados_helper deadlock; (bsc#1102230).

Fixed ntlm authentications with 'winbind use default domain = yes';
(bsc#1068059).

Fixed idmap_rid to have primary group other than 'Domain Users';
(bsc#1087931).

Fixed windows domain with one way trust that was not working (bsc#1087303).

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The version of Samba running on the remote host is 4.7.x prior to 4.7.12, or 4.8.x prior to 4.8.7, or 4.9.x prior to 4.9.3. It is, therefore, affected by multiple vulnerabilities.

Notes: 
  - Refer to vendor advisories for possible workarounds.
  - CVE-2018-16852 and CVE-2018-16857 only apply to 4.9.x.

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

New samba packages are available for Slackware 14.0, 14.1, 14.2, and
-current to fix security issues.

The samba project reports :

All versions of Samba from 4.0.0 onwards are vulnerable to infinite query recursion caused by CNAME loops. Any dns record can be added via ldap by an unprivileged user using the ldbadd tool, so this is a security issue.

When configured to accept smart-card authentication, Samba's KDC will call talloc_free() twice on the same memory if the principal in a validly signed certificate does not match the principal in the AS-REQ.

During the processing of an LDAP search before Samba's AD DC returns the LDAP entries to the client, the entries are cached in a single memory object with a maximum size of 256MB. When this size is reached, the Samba process providing the LDAP service will follow the NULL pointer, terminating the process.

During the processing of an DNS zone in the DNS management DCE/RPC server, the internal DNS server or the Samba DLZ plugin for BIND9, if the DSPROPERTY_ZONE_MASTER_SERVERS property or DSPROPERTY_ZONE_SCAVENGING_SERVERS property is set, the server will follow a NULL pointer and terminate

A user in a Samba AD domain can crash the KDC when Samba is built in the non-default MIT Kerberos configuration.

AD DC Configurations watching for bad passwords (to restrict brute forcing of passwords) in a window of more than 3 minutes may not watch for bad passwords at all.

ID	Name	Product	Family	Severity
134927	GLSA-202003-52 : Samba: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	critical
120862	Fedora 29 : 2:samba (2018-e423e8743f)	Nessus	Fedora Local Security Checks	medium
120763	Fedora 28 : 2:samba (2018-c2a93f8e1b)	Nessus	Fedora Local Security Checks	medium
120184	SUSE SLED15 / SLES15 Security Update : samba (SUSE-SU-2018:4066-1)	Nessus	SuSE Local Security Checks	medium
119306	Samba 4.7.x < 4.7.12 / 4.8.x < 4.8.7 / 4.9.x < 4.9.3 Multiple Vulnerabilities	Nessus	Misc.	medium
119280	Slackware 14.0 / 14.1 / 14.2 / current : samba (SSA:2018-333-01)	Nessus	Slackware Local Security Checks	medium
119246	FreeBSD : samba -- multiple vulnerabilities (54976998-f248-11e8-81e2-005056a311d1)	Nessus	FreeBSD Local Security Checks	medium

Detections

Analytics

CVE-2018-16853

medium

Tenable Plugins

critical

medium

medium

medium

medium

medium

medium