Vulnerabilities > CVE-2018-14345 - Improper Authentication vulnerability in Sddm Project Sddm

047910
CVSS 6.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
sddm-project
CWE-287
nessus
NVD
Published: 2018-07-17
Updated: 2019-10-03

Summary

An issue was discovered in SDDM through 0.17.0. If configured with ReuseSession=true, the password is not checked for users with an already existing session. Any user with access to the system D-Bus can therefore unlock any graphical session. This is related to daemon/Display.cpp and helper/backend/PamBackend.cpp.

Vulnerable Configurations

Part Description Count
Application
Sddm_Project
11

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.

Nessus

  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_F00ACDECB59F11E8805D001E2A3F778D.NASL
    descriptionMITRE reports : An issue was discovered in SDDM through 0.17.0. If configured with ReuseSession=true, the password is not checked for users with an already existing session. Any user with access to the system D-Bus can therefore unlock any graphical session. The default configuration of SDDM on FreeBSD is not affected, since it has ReuseSession=false.
    last seen2020-06-01
    modified2020-06-02
    plugin id117443
    published2018-09-12
    reporterThis script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/117443
    titleFreeBSD : X11 Session -- SDDM allows unauthorised unlocking (f00acdec-b59f-11e8-805d-001e2a3f778d)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2018 Jacques Vidrine and contributors
#
# Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
# HTML, PDF, PostScript, RTF and so forth) with or without modification,
# are permitted provided that the following conditions are met:
# 1. Redistributions of source code (VuXML) must retain the above
#    copyright notice, this list of conditions and the following
#    disclaimer as the first lines of this file unmodified.
# 2. Redistributions in compiled form (transformed to other DTDs,
#    published online in any format, converted to PDF, PostScript,
#    RTF and other formats) must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer
#    in the documentation and/or other materials provided with the
#    distribution.
# 
# THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

include("compat.inc");

if (description)
{
  script_id(117443);
  script_version("1.3");
  script_cvs_date("Date: 2018/11/10 11:49:47");

  script_cve_id("CVE-2018-14345");

  script_name(english:"FreeBSD : X11 Session -- SDDM allows unauthorised unlocking (f00acdec-b59f-11e8-805d-001e2a3f778d)");
  script_summary(english:"Checks for updated package in pkg_info output");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote FreeBSD host is missing a security-related update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"MITRE reports :

An issue was discovered in SDDM through 0.17.0. If configured with
ReuseSession=true, the password is not checked for users with an
already existing session. Any user with access to the system D-Bus can
therefore unlock any graphical session.

The default configuration of SDDM on FreeBSD is not affected, since it
has ReuseSession=false."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.suse.com/security/cve/CVE-2018-14345/"
  );
  # https://vuxml.freebsd.org/freebsd/f00acdec-b59f-11e8-805d-001e2a3f778d.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?e26ba01b"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:sddm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/08/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/12");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"FreeBSD Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");

  exit(0);
}


include("audit.inc");
include("freebsd_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (pkg_test(save_report:TRUE, pkg:"sddm<0.17.0_1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:pkg_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2018-862.NASL
    descriptionThis update for sddm fixes the following issues : The following security vulnerability was addressed : - CVE-2018-14345: Fixed the authentication, which did not check the password for users with an already existing session and allowed any user with access to the system bus to unlock any graphical session. (boo#1101450) The following other bugs were addressed : - Fallback to embedded theme, if none is set - Corrected section name for Wayland - Removed patch, which is no longer needed, because bug in libxcb was fixed in the meanwhile (boo#1099908)
    last seen2020-06-05
    modified2018-08-14
    plugin id111670
    published2018-08-14
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/111670
    titleopenSUSE Security Update : sddm (openSUSE-2018-862)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from openSUSE Security Update openSUSE-2018-862.
#
# The text description of this plugin is (C) SUSE LLC.
#

include("compat.inc");

if (description)
{
  script_id(111670);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");

  script_cve_id("CVE-2018-14345");

  script_name(english:"openSUSE Security Update : sddm (openSUSE-2018-862)");
  script_summary(english:"Check for the openSUSE-2018-862 patch");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote openSUSE host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"This update for sddm fixes the following issues :

The following security vulnerability was addressed :

  - CVE-2018-14345: Fixed the authentication, which did not
    check the password for users with an already existing
    session and allowed any user with access to the system
    bus to unlock any graphical session. (boo#1101450)

The following other bugs were addressed :

  - Fallback to embedded theme, if none is set

  - Corrected section name for Wayland

  - Removed patch, which is no longer needed, because bug in
    libxcb was fixed in the meanwhile (boo#1099908)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1099908"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1101450"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected sddm packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-branding-openSUSE");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-branding-upstream");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-debugsource");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.0");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/08/14");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"SuSE Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/SuSE/release", "Host/SuSE/rpm-list", "Host/cpu");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/SuSE/release");
if (isnull(release) || release =~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "openSUSE");
if (release !~ "^(SUSE15\.0)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.0", release);
if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

ourarch = get_kb_item("Host/cpu");
if (!ourarch) audit(AUDIT_UNKNOWN_ARCH);
if (ourarch !~ "^(x86_64)$") audit(AUDIT_ARCH_NOT, "x86_64", ourarch);

flag = 0;

if ( rpm_check(release:"SUSE15.0", reference:"sddm-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-branding-openSUSE-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-branding-upstream-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-debuginfo-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-debugsource-0.17.0-lp150.9.3.1") ) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "sddm / sddm-branding-openSUSE / sddm-branding-upstream / etc");
}
  • NASL familySuSE Local Security Checks
    NASL idOPENSUSE-2019-594.NASL
    descriptionThis update for sddm fixes the following issues : The following security vulnerability was addressed : - CVE-2018-14345: Fixed the authentication, which did not check the password for users with an already existing session and allowed any user with access to the system bus to unlock any graphical session. (boo#1101450) The following other bugs were addressed : - Fallback to embedded theme, if none is set - Corrected section name for Wayland - Removed patch, which is no longer needed, because bug in libxcb was fixed in the meanwhile (boo#1099908)
    last seen2020-06-01
    modified2020-06-02
    plugin id123257
    published2019-03-27
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/123257
    titleopenSUSE Security Update : sddm (openSUSE-2019-594)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from openSUSE Security Update openSUSE-2019-594.
#
# The text description of this plugin is (C) SUSE LLC.
#

include("compat.inc");

if (description)
{
  script_id(123257);
  script_version("1.2");
  script_cvs_date("Date: 2020/01/30");

  script_cve_id("CVE-2018-14345");

  script_name(english:"openSUSE Security Update : sddm (openSUSE-2019-594)");
  script_summary(english:"Check for the openSUSE-2019-594 patch");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote openSUSE host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"This update for sddm fixes the following issues :

The following security vulnerability was addressed :

  - CVE-2018-14345: Fixed the authentication, which did not
    check the password for users with an already existing
    session and allowed any user with access to the system
    bus to unlock any graphical session. (boo#1101450)

The following other bugs were addressed :

  - Fallback to embedded theme, if none is set

  - Corrected section name for Wayland

  - Removed patch, which is no longer needed, because bug in
    libxcb was fixed in the meanwhile (boo#1099908)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1099908"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugzilla.opensuse.org/show_bug.cgi?id=1101450"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected sddm packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-branding-openSUSE");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-branding-upstream");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:novell:opensuse:sddm-debugsource");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:novell:opensuse:15.0");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/07/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/03/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/03/27");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"SuSE Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/SuSE/release", "Host/SuSE/rpm-list", "Host/cpu");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/SuSE/release");
if (isnull(release) || release =~ "^(SLED|SLES)") audit(AUDIT_OS_NOT, "openSUSE");
if (release !~ "^(SUSE15\.0)$") audit(AUDIT_OS_RELEASE_NOT, "openSUSE", "15.0", release);
if (!get_kb_item("Host/SuSE/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

ourarch = get_kb_item("Host/cpu");
if (!ourarch) audit(AUDIT_UNKNOWN_ARCH);
if (ourarch !~ "^(x86_64)$") audit(AUDIT_ARCH_NOT, "x86_64", ourarch);

flag = 0;

if ( rpm_check(release:"SUSE15.0", reference:"sddm-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-branding-openSUSE-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-branding-upstream-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-debuginfo-0.17.0-lp150.9.3.1") ) flag++;
if ( rpm_check(release:"SUSE15.0", reference:"sddm-debugsource-0.17.0-lp150.9.3.1") ) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "sddm / sddm-branding-openSUSE / sddm-branding-upstream / etc");
}

References