Ubuntu 20.04 LTS / 22.04 LTS : GnuTLS vulnerability (USN-5901-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5901-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(171967);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id("CVE-2023-0361");
  script_xref(name:"USN", value:"5901-1");

  script_name(english:"Ubuntu 20.04 LTS / 22.04 LTS : GnuTLS vulnerability (USN-5901-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 20.04 LTS / 22.04 LTS host has packages installed that are affected by a vulnerability as referenced
in the USN-5901-1 advisory.

  - A timing side-channel in the handling of RSA ClientKeyExchange messages was discovered in GnuTLS. This
    side-channel can be sufficient to recover the key encrypted in the RSA ciphertext across a network in a
    Bleichenbacher style attack. To achieve a successful decryption the attacker would need to send a large
    amount of specially crafted messages to the vulnerable server. By recovering the secret from the
    ClientKeyExchange message, the attacker would be able to decrypt the application data exchanged over that
    connection. (CVE-2023-0361)

Note that Nessus has not tested for this issue 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-5901-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/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:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-0361");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/02/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/02/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/02/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gnutls-bin");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:guile-gnutls");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgnutls-dane0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgnutls-openssl27");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgnutls28-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgnutls30");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgnutlsxx28");
  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) 2023 Canonical, Inc. / NASL script (C) 2023 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 (! ('20.04' >< os_release || '22.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 20.04 / 22.04', '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': '20.04', 'pkgname': 'gnutls-bin', 'pkgver': '3.6.13-2ubuntu1.8'},
    {'osver': '20.04', 'pkgname': 'guile-gnutls', 'pkgver': '3.6.13-2ubuntu1.8'},
    {'osver': '20.04', 'pkgname': 'libgnutls-dane0', 'pkgver': '3.6.13-2ubuntu1.8'},
    {'osver': '20.04', 'pkgname': 'libgnutls-openssl27', 'pkgver': '3.6.13-2ubuntu1.8'},
    {'osver': '20.04', 'pkgname': 'libgnutls28-dev', 'pkgver': '3.6.13-2ubuntu1.8'},
    {'osver': '20.04', 'pkgname': 'libgnutls30', 'pkgver': '3.6.13-2ubuntu1.8'},
    {'osver': '20.04', 'pkgname': 'libgnutlsxx28', 'pkgver': '3.6.13-2ubuntu1.8'},
    {'osver': '22.04', 'pkgname': 'gnutls-bin', 'pkgver': '3.7.3-4ubuntu1.2'},
    {'osver': '22.04', 'pkgname': 'guile-gnutls', 'pkgver': '3.7.3-4ubuntu1.2'},
    {'osver': '22.04', 'pkgname': 'libgnutls-dane0', 'pkgver': '3.7.3-4ubuntu1.2'},
    {'osver': '22.04', 'pkgname': 'libgnutls-openssl27', 'pkgver': '3.7.3-4ubuntu1.2'},
    {'osver': '22.04', 'pkgname': 'libgnutls28-dev', 'pkgver': '3.7.3-4ubuntu1.2'},
    {'osver': '22.04', 'pkgname': 'libgnutls30', 'pkgver': '3.7.3-4ubuntu1.2'},
    {'osver': '22.04', 'pkgname': 'libgnutlsxx28', 'pkgver': '3.7.3-4ubuntu1.2'}
];

var flag = 0;
foreach 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)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'gnutls-bin / guile-gnutls / libgnutls-dane0 / libgnutls-openssl27 / etc');
}