Vulnerabilities > CVE-2019-18420 - Use of Externally-Controlled Format String vulnerability in multiple products

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory FEDORA-2019-cbb732f760.
#

include("compat.inc");

if (description)
{
  script_id(131460);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/07/10");

  script_cve_id("CVE-2018-12207", "CVE-2019-11135", "CVE-2019-18420", "CVE-2019-18421", "CVE-2019-18422", "CVE-2019-18423", "CVE-2019-18424", "CVE-2019-18425");
  script_xref(name:"FEDORA", value:"2019-cbb732f760");
  script_xref(name:"IAVB", value:"2019-B-0084-S");

  script_name(english:"Fedora 30 : xen (2019-cbb732f760)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"add missing XSA-299 patches x86: Machine Check Error on Page Size
Change DoS [XSA-304, CVE-2018-12207] TSX Asynchronous Abort
speculative side channel [XSA-305, CVE-2019-11135]

----

VCPUOP_initialise DoS [XSA-296, CVE-2019-18420] missing descriptor
table limit checking in x86 PV emulation [XSA-298, CVE-2019-18425]
Issues with restartable PV type change operations [XSA-299,
CVE-2019-18421] (#1767726) add-to-physmap can be abused to DoS Arm
hosts [XSA-301, CVE-2019-18423] passed through PCI devices may corrupt
host memory after deassignment [XSA-302, CVE-2019-18424] (#1767731)
ARM: Interrupts are unconditionally unmasked in exception handlers
[XSA-303, CVE-2019-18422]

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora update system website.
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://bodhi.fedoraproject.org/updates/FEDORA-2019-cbb732f760"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected xen package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
  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:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  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:fedoraproject:fedora:xen");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:30");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/10/31");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/11/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/12/03");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Fedora Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^30([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 30", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) 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, "Fedora", cpu);


flag = 0;
if (rpm_check(release:"FC30", reference:"xen-4.11.2-3.fc30")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "xen");
}