CentOS 7 : ntp (CESA-2018:0855)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:0855 and 
# CentOS Errata and Security Advisory 2018:0855 respectively.
#

include("compat.inc");

if (description)
{
  script_id(109375);
  script_version("1.4");
  script_cvs_date("Date: 2019/12/31");

  script_cve_id("CVE-2017-6462", "CVE-2017-6463", "CVE-2017-6464");
  script_xref(name:"RHSA", value:"2018:0855");

  script_name(english:"CentOS 7 : ntp (CESA-2018:0855)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote CentOS host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"An update for ntp is now available for Red Hat Enterprise Linux 7.

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

The Network Time Protocol (NTP) is used to synchronize a computer's
time with another referenced time source. These packages include the
ntpd service which continuously adjusts system time and utilities used
to query and configure the ntpd service.

Security Fix(es) :

* ntp: Authenticated DoS via Malicious Config Option (CVE-2017-6463)

* ntp: Denial of Service via Malformed Config (CVE-2017-6464)

* ntp: Buffer Overflow in DPTS Clock (CVE-2017-6462)

For more details about the security issue(s), including the impact, a
CVSS score, and other related information, refer to the CVE page(s)
listed in the References section.

Red Hat would like to thank the NTP project for reporting these
issues. Upstream acknowledges Cure53 as the original reporter of these
issues.

Additional Changes :

For detailed information on changes in this release, see the Red Hat
Enterprise Linux 7.5 Release Notes linked from the References section."
  );
  # https://lists.centos.org/pipermail/centos-cr-announce/2018-April/004998.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?3cbc9e8e"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected ntp packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-6462");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:ntp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:ntp-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:ntp-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:ntpdate");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:sntp");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/03/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/04/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/04/27");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"CentOS Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/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/CentOS/release");
if (isnull(release) || "CentOS" >!< release) audit(AUDIT_OS_NOT, "CentOS");
os_ver = pregmatch(pattern: "CentOS(?: Linux)? release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "CentOS");
os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "CentOS 7.x", "CentOS " + os_ver);

if (!get_kb_item("Host/CentOS/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, "CentOS", cpu);


flag = 0;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"ntp-4.2.6p5-28.el7.centos")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"ntp-doc-4.2.6p5-28.el7.centos")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"ntp-perl-4.2.6p5-28.el7.centos")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"ntpdate-4.2.6p5-28.el7.centos")) flag++;
if (rpm_check(release:"CentOS-7", cpu:"x86_64", reference:"sntp-4.2.6p5-28.el7.centos")) flag++;


if (flag)
{
  cr_plugin_caveat = '\n' +
    'NOTE: The security advisory associated with this vulnerability has a\n' +
    'fixed package version that may only be available in the continuous\n' +
    'release (CR) repository for CentOS, until it is present in the next\n' +
    'point release of CentOS.\n\n' +

    'If an equal or higher package level does not exist in the baseline\n' +
    'repository for your major version of CentOS, then updates from the CR\n' +
    'repository will need to be applied in order to address the\n' +
    'vulnerability.\n';
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get() + cr_plugin_caveat
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "ntp / ntp-doc / ntp-perl / ntpdate / sntp");
}