Ubuntu 16.04 LTS / 18.04 LTS / 18.10 / 19.04 : GnuTLS vulnerabilities (USN-3999-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3999-1. 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(125622);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/09/17");

  script_cve_id("CVE-2018-10844", "CVE-2018-10845", "CVE-2018-10846", "CVE-2019-3829", "CVE-2019-3836");
  script_xref(name:"USN", value:"3999-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 18.10 / 19.04 : GnuTLS vulnerabilities (USN-3999-1)");
  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:
"Eyal Ronen, Kenneth G. Paterson, and Adi Shamir discovered that GnuTLS
was vulnerable to a timing side-channel attack known as the 'Lucky
Thirteen' issue. A remote attacker could possibly use this issue to
perform plaintext-recovery attacks via analysis of timing data. This
issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.
(CVE-2018-10844, CVE-2018-10845, CVE-2018-10846)

Tavis Ormandy discovered that GnuTLS incorrectly handled memory when
verifying certain X.509 certificates. A remote attacker could use this
issue to cause GnuTLS to crash, resulting in a denial of service, or
possibly execute arbitrary code. This issue only affected Ubuntu 18.04
LTS, Ubuntu 18.10, and Ubuntu 19.04. (CVE-2019-3829)

It was discovered that GnuTLS incorrectly handled certain
post-handshake messages. A remote attacker could use this issue to
cause GnuTLS to crash, resulting in a denial of service, or possibly
execute arbitrary code. This issue only affected Ubuntu 18.10 and
Ubuntu 19.04. (CVE-2019-3836).

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/3999-1/"
  );
  script_set_attribute(
    attribute:"solution",
    value:"Update the affected libgnutls30 package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:N");
  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:N/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-10845");
  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:libgnutls30");
  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:"2018/08/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/05/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/31");
  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:"libgnutls30", pkgver:"3.4.10-4ubuntu1.5")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libgnutls30", pkgver:"3.5.18-1ubuntu1.1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libgnutls30", pkgver:"3.6.4-2ubuntu1.2")) flag++;
if (ubuntu_check(osver:"19.04", pkgname:"libgnutls30", pkgver:"3.6.5-2ubuntu1.1")) 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, "libgnutls30");
}