Vulnerabilities > CVE-2018-6119 - Improper Input Validation vulnerability in Google Chrome

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
HIGH
Availability impact
NONE
network
low complexity
google
CWE-20
nessus
NVD
Published: 2018-09-25
Updated: 2024-11-21

Summary

Incorrect security UI in Omnibox in Google Chrome prior to 64.0.3282.119 allowed a remote attacker to spoof the contents of the Omnibox (URL bar) via a crafted HTML page.

Vulnerable Configurations

Part Description Count
Application
Google
3866

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-39BE36E9FC.NASL
    descriptionSecurity fixes for CVE-2018-6055 CVE-2018-6119 CVE-2018-16429 CVE-2018-16428 ---- Update to Chromium 69. (EPEL-7 update is blocked by a GCC bug: 1629813, so as soon as devtoolset-8 arrives...) Fixes a lot of security issues, like every major release of Chromium, including CVE-2018-16087 CVE-2018-16088 CVE-2018-16086CVE-2018-16065 CVE-2018-16066 CVE-2018-16067 CVE-2018-16068 CVE-2018-16069 CVE-2018-16070 CVE-2018-16071 CVE-2018-16072 CVE-2018-16073 CVE-2018-16074 CVE-2018-16075 CVE-2018-16076 CVE-2018-16077 CVE-2018-16078 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.
    last seen2020-06-05
    modified2019-01-03
    plugin id120356
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120356
    titleFedora 29 : chromium (2018-39be36e9fc)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory FEDORA-2018-39be36e9fc.
#

include("compat.inc");

if (description)
{
  script_id(120356);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");

  script_cve_id("CVE-2018-16065", "CVE-2018-16066", "CVE-2018-16067", "CVE-2018-16068", "CVE-2018-16069", "CVE-2018-16070", "CVE-2018-16071", "CVE-2018-16072", "CVE-2018-16073", "CVE-2018-16074", "CVE-2018-16075", "CVE-2018-16076", "CVE-2018-16077", "CVE-2018-16078", "CVE-2018-16079", "CVE-2018-16080", "CVE-2018-16081", "CVE-2018-16082", "CVE-2018-16083", "CVE-2018-16084", "CVE-2018-16085", "CVE-2018-16086", "CVE-2018-16087", "CVE-2018-16088", "CVE-2018-16428", "CVE-2018-16429", "CVE-2018-17458", "CVE-2018-17459", "CVE-2018-6055", "CVE-2018-6119");
  script_xref(name:"FEDORA", value:"2018-39be36e9fc");

  script_name(english:"Fedora 29 : chromium (2018-39be36e9fc)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Security fixes for CVE-2018-6055 CVE-2018-6119 CVE-2018-16429
CVE-2018-16428

----

Update to Chromium 69. (EPEL-7 update is blocked by a GCC bug:
1629813, so as soon as devtoolset-8 arrives...)

Fixes a lot of security issues, like every major release of Chromium,
including CVE-2018-16087 CVE-2018-16088 CVE-2018-16086CVE-2018-16065
CVE-2018-16066 CVE-2018-16067 CVE-2018-16068 CVE-2018-16069
CVE-2018-16070 CVE-2018-16071 CVE-2018-16072 CVE-2018-16073
CVE-2018-16074 CVE-2018-16075 CVE-2018-16076 CVE-2018-16077
CVE-2018-16078

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."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bodhi.fedoraproject.org/updates/FEDORA-2018-39be36e9fc"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected chromium package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:chromium");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:29");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/09/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/10/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/01/03");
  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:"Fedora Local Security Checks");

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

  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/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^29([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 29", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu);


flag = 0;
if (rpm_check(release:"FC29", reference:"chromium-69.0.3497.100-1.fc29")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "chromium");
}
  • NASL familyRed Hat Local Security Checks
    NASL idREDHAT-RHSA-2018-0265.NASL
    descriptionAn update for chromium-browser is now available for Red Hat Enterprise Linux 6 Supplementary. Red Hat Product Security has rated this update as having a security impact of Important. 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. Chromium is an open source web browser, powered by WebKit (Blink). This update upgrades Chromium to version 64.0.3282.119. Security Fix(es) : * Multiple flaws were found in the processing of malformed web content. A web page containing malicious content could cause Chromium to crash, execute arbitrary code, or disclose sensitive information when visited by the victim. (CVE-2018-6031, CVE-2018-6032, CVE-2018-6033, CVE-2018-6034, CVE-2018-6035, CVE-2018-6036, CVE-2018-6037, CVE-2018-6038, CVE-2018-6039, CVE-2018-6040, CVE-2018-6041, CVE-2018-6042, CVE-2018-6043, CVE-2018-6045, CVE-2018-6046, CVE-2018-6047, CVE-2018-6048, CVE-2018-6049, CVE-2018-6050, CVE-2018-6051, CVE-2018-6052, CVE-2018-6053, CVE-2018-6054) * To mitigate timing-based side-channel attacks similar to
    last seen2020-05-31
    modified2018-02-02
    plugin id106574
    published2018-02-02
    reporterThis script is Copyright (C) 2018-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/106574
    titleRHEL 6 : chromium-browser (RHSA-2018:0265)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:0265. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(106574);
  script_version("3.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/29");

  script_cve_id("CVE-2018-6031", "CVE-2018-6032", "CVE-2018-6033", "CVE-2018-6034", "CVE-2018-6035", "CVE-2018-6036", "CVE-2018-6037", "CVE-2018-6038", "CVE-2018-6039", "CVE-2018-6040", "CVE-2018-6041", "CVE-2018-6042", "CVE-2018-6043", "CVE-2018-6045", "CVE-2018-6046", "CVE-2018-6047", "CVE-2018-6048", "CVE-2018-6049", "CVE-2018-6050", "CVE-2018-6051", "CVE-2018-6052", "CVE-2018-6053", "CVE-2018-6054", "CVE-2018-6055", "CVE-2018-6119");
  script_xref(name:"RHSA", value:"2018:0265");

  script_name(english:"RHEL 6 : chromium-browser (RHSA-2018:0265)");
  script_summary(english:"Checks the rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis",
    value:"The remote Red Hat host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description",
    value:
"An update for chromium-browser is now available for Red Hat Enterprise
Linux 6 Supplementary.

Red Hat Product Security has rated this update as having a security
impact of Important. 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.

Chromium is an open source web browser, powered by WebKit (Blink).

This update upgrades Chromium to version 64.0.3282.119.

Security Fix(es) :

* Multiple flaws were found in the processing of malformed web
content. A web page containing malicious content could cause Chromium
to crash, execute arbitrary code, or disclose sensitive information
when visited by the victim. (CVE-2018-6031, CVE-2018-6032,
CVE-2018-6033, CVE-2018-6034, CVE-2018-6035, CVE-2018-6036,
CVE-2018-6037, CVE-2018-6038, CVE-2018-6039, CVE-2018-6040,
CVE-2018-6041, CVE-2018-6042, CVE-2018-6043, CVE-2018-6045,
CVE-2018-6046, CVE-2018-6047, CVE-2018-6048, CVE-2018-6049,
CVE-2018-6050, CVE-2018-6051, CVE-2018-6052, CVE-2018-6053,
CVE-2018-6054)

* To mitigate timing-based side-channel attacks similar to 'Spectre'
and 'Meltdown', this update reduces the precision of the timing data
provided by the Date object and the performance.now() API, and the V8
JavaScript engine now uses masking of certain addresses and array or
string indices."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://chromereleases.googleblog.com/2018/01/"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHSA-2018:0265"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6031"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6032"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6033"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6034"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6035"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6036"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6037"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6038"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6039"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6040"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6041"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6042"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6043"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6045"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6046"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6047"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6048"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6049"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6050"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6051"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6052"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6053"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6054"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6055"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-6119"
  );
  script_set_attribute(
    attribute:"solution",
    value:
"Update the affected chromium-browser and / or
chromium-browser-debuginfo packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/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:L/PR:N/UI:R/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:"exploit_available", value:"false");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:chromium-browser");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:chromium-browser-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/09/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/02/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/02/02");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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:"Red Hat Local Security Checks");

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

  exit(0);
}


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

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Red Hat" >!< release) audit(AUDIT_OS_NOT, "Red Hat");
os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Red Hat");
os_ver = os_ver[1];
if (! preg(pattern:"^6([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Red Hat 6.x", "Red Hat " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "s390" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Red Hat", cpu);

yum_updateinfo = get_kb_item("Host/RedHat/yum-updateinfo");
if (!empty_or_null(yum_updateinfo)) 
{
  rhsa = "RHSA-2018:0265";
  yum_report = redhat_generate_yum_updateinfo_report(rhsa:rhsa);
  if (!empty_or_null(yum_report))
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : yum_report 
    );
    exit(0);
  }
  else
  {
    audit_message = "affected by Red Hat security advisory " + rhsa;
    audit(AUDIT_OS_NOT, audit_message);
  }
}
else
{
  flag = 0;
  if (rpm_check(release:"RHEL6", cpu:"i686", reference:"chromium-browser-64.0.3282.119-1.el6_9", allowmaj:TRUE)) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"chromium-browser-64.0.3282.119-1.el6_9", allowmaj:TRUE)) flag++;
  if (rpm_check(release:"RHEL6", cpu:"i686", reference:"chromium-browser-debuginfo-64.0.3282.119-1.el6_9", allowmaj:TRUE)) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"chromium-browser-debuginfo-64.0.3282.119-1.el6_9", allowmaj:TRUE)) flag++;

  if (flag)
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : rpm_report_get() + redhat_report_package_caveat()
    );
    exit(0);
  }
  else
  {
    tested = pkg_tests_get();
    if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
    else audit(AUDIT_PACKAGE_NOT_INSTALLED, "chromium-browser / chromium-browser-debuginfo");
  }
}
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2018-F76E6D17F1.NASL
    descriptionSecurity fixes for CVE-2018-6055 CVE-2018-6119 CVE-2018-16429 CVE-2018-16428 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.
    last seen2020-06-05
    modified2019-01-03
    plugin id120923
    published2019-01-03
    reporterThis script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/120923
    titleFedora 28 : chromium (2018-f76e6d17f1)

Redhat

rpms
  • chromium-browser-0:64.0.3282.119-1.el6_9
  • chromium-browser-debuginfo-0:64.0.3282.119-1.el6_9

References