Linux Distros Unpatched Vulnerability : CVE-2019-19580

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

include('compat.inc');

if (description)
{
  script_id(258474);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/29");

  script_cve_id("CVE-2019-19580");

  script_name(english:"Linux Distros Unpatched Vulnerability : CVE-2019-19580");

  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.

  - An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by
    leveraging race conditions in pagetable promotion and demotion operations, because of an incomplete fix
    for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations.
    Despite extensive testing and auditing, some corner cases were missed. A malicious PV guest administrator
    may be able to escalate their privilege to that of the host. All security-supported versions of Xen are
    vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage
    the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Note that these attacks
    require very precise timing, which may be difficult to exploit in practice. (CVE-2019-19580)

Note that Nessus relies on the presence of the package as reported by the vendor.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/CVE-2019-19580");
  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:N/AC:M/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:U/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:U/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-19580");

  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:"2019/12/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/08/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:"p-cpe:/a:canonical:ubuntu_linux:xen");
  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) 2025-2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl", "set_linux_os_id.nasl");
  script_require_keys("Host/cpu", "Host/local_checks_enabled", "global_settings/vendor_unpatched", "Host/OS/identifier");
  script_require_ports("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/Debian/dpkg-l"))) audit(AUDIT_PACKAGE_LIST_MISSING);

include('linux_unpatched.inc');

var distro_constraints_array = {
  "Ubuntu Linux-16.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "16.04",
        "pkgs": [
          {"reference": "libxen-4.6"},
          {"reference": "libxen-dev"},
          {"reference": "libxenstore3.0"},
          {"reference": "xen-hypervisor-4.4-amd64"},
          {"reference": "xen-hypervisor-4.4-arm64"},
          {"reference": "xen-hypervisor-4.4-armhf"},
          {"reference": "xen-hypervisor-4.5-amd64"},
          {"reference": "xen-hypervisor-4.5-arm64"},
          {"reference": "xen-hypervisor-4.5-armhf"},
          {"reference": "xen-hypervisor-4.6-amd64"},
          {"reference": "xen-hypervisor-4.6-arm64"},
          {"reference": "xen-hypervisor-4.6-armhf"},
          {"reference": "xen-system-amd64"},
          {"reference": "xen-system-arm64"},
          {"reference": "xen-system-armhf"},
          {"reference": "xen-utils-4.6"},
          {"reference": "xen-utils-common"},
          {"reference": "xenstore-utils"}
        ]
      }
    ]
  },
  "Ubuntu Linux-18.04": {
    "package_manager": "dpkg-l",
    "constraints": [
      {
        "release": "18.04",
        "pkgs": [
          {"reference": "libxen-4.9"},
          {"reference": "libxen-dev"},
          {"reference": "libxenstore3.0"},
          {"reference": "xen-hypervisor-4.6-amd64"},
          {"reference": "xen-hypervisor-4.6-arm64"},
          {"reference": "xen-hypervisor-4.6-armhf"},
          {"reference": "xen-hypervisor-4.7-amd64"},
          {"reference": "xen-hypervisor-4.7-arm64"},
          {"reference": "xen-hypervisor-4.7-armhf"},
          {"reference": "xen-hypervisor-4.8-amd64"},
          {"reference": "xen-hypervisor-4.8-arm64"},
          {"reference": "xen-hypervisor-4.8-armhf"},
          {"reference": "xen-hypervisor-4.9-amd64"},
          {"reference": "xen-hypervisor-4.9-arm64"},
          {"reference": "xen-hypervisor-4.9-armhf"},
          {"reference": "xen-system-amd64"},
          {"reference": "xen-system-arm64"},
          {"reference": "xen-system-armhf"},
          {"reference": "xen-utils-4.9"},
          {"reference": "xen-utils-common"},
          {"reference": "xenstore-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 third_party_support = get_kb_item('Host/OS/extended-third-party');
if (!empty_or_null(third_party_support)) {
    var third_party_vendors = distro_constraints_values['third_party'];
    if (!empty_or_null(third_party_vendors)) {
        var vendor;
        foreach vendor (third_party_vendors) {
            if (vendor == third_party_support) exit(0, 'A third party management patch is available for this vulnerability from ' + vendor + '.\n');
        }
    }
}

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_WARNING,
      extra      : report
  );
  exit(0);
}
else
{
  audit(AUDIT_HOST_NOT, 'affected');
}