Ubuntu 16.04 LTS / 18.04 LTS / 18.10 / 19.04 : bind9 vulnerability (USN-3956-1)

2019-04-26T00:00:00
ID UBUNTU_USN-3956-1.NASL
Type nessus
Reporter Ubuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-02-02T00:00:00

Description

It was discovered that Bind incorrectly handled limiting the number of simultaneous TCP clients. A remote attacker could possibly use this issue to cause Bind to consume resources, leading to a denial of service.

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

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3956-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(124323);
  script_version("1.4");
  script_cvs_date("Date: 2020/01/21");

  script_cve_id("CVE-2018-5743");
  script_xref(name:"USN", value:"3956-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 18.10 / 19.04 : bind9 vulnerability (USN-3956-1)");
  script_summary(english:"Checks dpkg output for updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Ubuntu host is missing a security-related patch."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"It was discovered that Bind incorrectly handled limiting the number of
simultaneous TCP clients. A remote attacker could possibly use this
issue to cause Bind to consume resources, leading to a denial of
service.

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu security advisory. 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://usn.ubuntu.com/3956-1/"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected bind9 package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/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:N/S:U/C:N/I:N/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:canonical:ubuntu_linux:bind9");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:19.04");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/10/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/04/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/04/26");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! preg(pattern:"^(16\.04|18\.04|18\.10|19\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 16.04 / 18.04 / 18.10 / 19.04", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) 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, "Ubuntu", cpu);

flag = 0;

if (ubuntu_check(osver:"16.04", pkgname:"bind9", pkgver:"1:9.10.3.dfsg.P4-8ubuntu1.14")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"bind9", pkgver:"1:9.11.3+dfsg-1ubuntu1.7")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"bind9", pkgver:"1:9.11.4+dfsg-3ubuntu5.3")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"bind9", pkgver:"1:9.11.5.P1+dfsg-1ubuntu2.3")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "bind9");
}