Linux Distros Unpatched Vulnerability : CVE-2018-16868

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(222306);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/09/03");

  script_cve_id("CVE-2018-16868");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2018-16868");

  script_set_attribute(attribute:"synopsis", value:
"The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be
patched.");
  script_set_attribute(attribute:"description", value:
"The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied
patch available.

  - A Bleichenbacher type side-channel based padding oracle attack was found in the way gnutls handles
    verification of RSA decrypted PKCS#1 v1.5 data. An attacker who is able to run process on the same
    physical core as the victim process, could use this to extract plaintext or in some cases downgrade any
    TLS connections to a vulnerable server. (CVE-2018-16868)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2018-16868");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2018-16868");
  script_set_attribute(attribute:"solution", value:
"There is no known solution at this time.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:P/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:P/AC:H/PR:L/UI:N/S:C/C:H/I:L/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-2018-16868");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/11/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/03/04");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:centos:centos:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gnutls26");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gnutls28");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gnutls");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gnutls-c++");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gnutls-dane");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gnutls-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gnutls-guile");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:centos:centos:gnutls-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnutls");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnutls-c++");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnutls-dane");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnutls-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnutls-guile");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:gnutls-utils");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("set_linux_os_id.nasl", "ssh_get_info2.nasl");
  script_require_keys("Host/OS/identifier", "Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched");
  script_require_ports("Host/OS/CentOS Linux-7", "Host/OS/Red Hat Enterprise Linux-5", "Host/OS/Red Hat Enterprise Linux-6", "Host/OS/Red Hat Enterprise Linux-7", "Host/OS/Ubuntu Linux-14.04", "Host/OS/Ubuntu Linux-16.04", "Host/OS/Ubuntu Linux-18.04");

  exit(0);
}

if (!get_kb_item("global_settings/vendor_unpatched")) exit(0, "Unpatched Vulnerabilities Detection not active.");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (empty_or_null(get_one_kb_item("Host/CentOS/rpm-list")) && empty_or_null(get_one_kb_item("Host/Debian/dpkg-l")) && empty_or_null(get_one_kb_item("Host/RedHat/rpm-list"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Ubuntu Linux-14.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "14.04",
        "pkgs": [
          {"reference": "gnutls-bin"},
          {"reference": "gnutls26-doc"},
          {"reference": "libgnutls-dev"},
          {"reference": "libgnutls-openssl27"},
          {"reference": "libgnutls26"},
          {"reference": "libgnutls26-dbg"},
          {"reference": "libgnutlsxx27"}
        ]
      }
    ]
  },
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "gnutls-bin"},
          {"reference": "gnutls-doc"},
          {"reference": "guile-gnutls"},
          {"reference": "libgnutls-dev"},
          {"reference": "libgnutls-openssl27"},
          {"reference": "libgnutls28-dev"},
          {"reference": "libgnutls30"},
          {"reference": "libgnutlsxx28"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "gnutls-bin"},
          {"reference": "gnutls-doc"},
          {"reference": "libgnutls-dane0"},
          {"reference": "libgnutls-openssl27"},
          {"reference": "libgnutls28-dev"},
          {"reference": "libgnutls30"},
          {"reference": "libgnutlsxx28"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-5": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "5",
        "pkgs": [
          {"reference": "gnutls"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-6": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "6",
        "pkgs": [
          {"reference": "gnutls"},
          {"reference": "gnutls-devel"},
          {"reference": "gnutls-guile"},
          {"reference": "gnutls-utils"}
        ]
      }
    ]
  },
  "CentOS Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "gnutls"},
          {"reference": "gnutls-c++"},
          {"reference": "gnutls-dane"},
          {"reference": "gnutls-devel"},
          {"reference": "gnutls-utils"}
        ]
      }
    ]
  },
  "Red Hat Enterprise Linux-7": {
    "package_manager": "rpm-list",
    "constraints": [
      {
        "release": "7",
        "pkgs": [
          {"reference": "gnutls"},
          {"reference": "gnutls-c++"},
          {"reference": "gnutls-dane"},
          {"reference": "gnutls-devel"},
          {"reference": "gnutls-utils"}
        ]
      }
    ]
  }
};

var distro_constraints_values = linux_unpatched::get_distro_constraints(distro_constraints_arr:distro_constraints_array);
if (empty_or_null(distro_constraints_values)) audit(AUDIT_HOST_NOT, 'affected');
var report = linux_unpatched::check_unpatched_constraints(distro_constraints_values:distro_constraints_values);

if (!empty_or_null(report))
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_NOTE,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}