Debian DLA-2201-1 : ntp security update

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-2201-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(136366);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/03/13");

  script_cve_id("CVE-2020-11868");

  script_name(english:"Debian DLA-2201-1 : ntp security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"A Denial of Service (DoS) vulnerability was discovered in the network
time protocol server/client, ntp.

ntp allowed an 'off-path' attacker to block unauthenticated
synchronisation via a server mode packet with a spoofed source IP
address because transmissions were rescheduled even if a packet lacked
a valid 'origin timestamp'

For Debian 8 'Jessie', this issue has been fixed in ntp version
1:4.2.6.p5+dfsg-7+deb8u3.

We recommend that you upgrade your ntp packages.

NOTE: Tenable Network Security has extracted the preceding description
block directly from the DLA 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://lists.debian.org/debian-lts-announce/2020/05/msg00004.html");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/jessie/ntp");
  script_set_attribute(attribute:"solution", value:
"Upgrade the affected ntp, ntp-doc, and ntpdate packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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:"cvss_score_source", value:"CVE-2020-11868");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/05/05");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/07");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ntp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ntp-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:ntpdate");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Debian Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


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


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;
if (deb_check(release:"8.0", prefix:"ntp", reference:"1:4.2.6.p5+dfsg-7+deb8u3")) flag++;
if (deb_check(release:"8.0", prefix:"ntp-doc", reference:"1:4.2.6.p5+dfsg-7+deb8u3")) flag++;
if (deb_check(release:"8.0", prefix:"ntpdate", reference:"1:4.2.6.p5+dfsg-7+deb8u3")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");