Ubuntu 14.04 LTS / 16.04 LTS : Libksba vulnerabilities (USN-2982-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-2982-1. 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(91220);
  script_version("2.14");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  script_cve_id(
    "CVE-2016-4353",
    "CVE-2016-4354",
    "CVE-2016-4355",
    "CVE-2016-4356",
    "CVE-2016-4574",
    "CVE-2016-4579"
  );
  script_xref(name:"USN", value:"2982-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS : Libksba vulnerabilities (USN-2982-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 14.04 LTS / 16.04 LTS host has packages installed that are affected by multiple vulnerabilities as
referenced in the USN-2982-1 advisory.

    Hanno Bck discovered that Libksba incorrectly handled decoding certain BER data. An attacker could use
    this issue to cause Libksba to crash, resulting in a denial of service. This issue only applied to Ubuntu
    12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4353)

    Hanno Bck discovered that Libksba incorrectly handled decoding certain BER data. An attacker could use
    this issue to cause Libksba to crash, resulting in a denial of service, or possibly execute arbitrary
    code. This issue only applied to Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-4354, CVE-2016-4355)

    Hanno Bck discovered that Libksba incorrectly handled incorrect utf-8 strings when decoding certain DN
    data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or
    possibly execute arbitrary code. This issue only applied to Ubuntu 12.04 LTS and Ubuntu 14.04 LTS.
    (CVE-2016-4356)

    Pascal Cuoq discovered that Libksba incorrectly handled incorrect utf-8 strings when decoding certain DN
    data. An attacker could use this issue to cause Libksba to crash, resulting in a denial of service, or
    possibly execute arbitrary code. (CVE-2016-4574)

    Pascal Cuoq discovered that Libksba incorrectly handled decoding certain data. An attacker could use this
    issue to cause Libksba to crash, resulting in a denial of service. (CVE-2016-4579)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-2982-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected libksba-dev and / or libksba8 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-2016-4579");

  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:"2016/06/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/05/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/05/18");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libksba8");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libksba-dev");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2016-2024 Canonical, Inc. / NASL script (C) 2016-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include('debian_package.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('14.04' >< os_release || '16.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '14.04', 'pkgname': 'libksba-dev', 'pkgver': '1.3.0-3ubuntu0.14.04.2'},
    {'osver': '14.04', 'pkgname': 'libksba8', 'pkgver': '1.3.0-3ubuntu0.14.04.2'},
    {'osver': '16.04', 'pkgname': 'libksba-dev', 'pkgver': '1.3.3-1ubuntu0.16.04.1'},
    {'osver': '16.04', 'pkgname': 'libksba8', 'pkgver': '1.3.3-1ubuntu0.16.04.1'}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libksba-dev / libksba8');
}