Fedora 38 : xen (2023-56901a79a1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2023-56901a79a1
#

include('compat.inc');

if (description)
{
  script_id(186460);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/04/29");

  script_cve_id("CVE-2023-46835", "CVE-2023-46836");
  script_xref(name:"FEDORA", value:"2023-56901a79a1");
  script_xref(name:"IAVB", value:"2023-B-0090");

  script_name(english:"Fedora 38 : xen (2023-56901a79a1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Fedora host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Fedora 38 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2023-56901a79a1 advisory.

  - The current setup of the quarantine page tables assumes that the quarantine domain (dom_io) has been
    initialized with an address width of DEFAULT_DOMAIN_ADDRESS_WIDTH (48) and hence 4 page table levels.
    However dom_io being a PV domain gets the AMD-Vi IOMMU page tables levels based on the maximum (hot
    pluggable) RAM address, and hence on systems with no RAM above the 512GB mark only 3 page-table levels are
    configured in the IOMMU. On systems without RAM above the 512GB boundary amd_iommu_quarantine_init() will
    setup page tables for the scratch page with 4 levels, while the IOMMU will be configured to use 3 levels
    only, resulting in the last page table directory (PDE) effectively becoming a page table entry (PTE), and
    hence a device in quarantine mode gaining write access to the page destined to be a PDE. Due to this page
    table level mismatch, the sink page the device gets read/write access to is no longer cleared between
    device assignment, possibly leading to data leaks. (CVE-2023-46835)

  - The fixes for XSA-422 (Branch Type Confusion) and XSA-434 (Speculative Return Stack Overflow) are not IRQ-
    safe. It was believed that the mitigations always operated in contexts with IRQs disabled. However, the
    original XSA-254 fix for Meltdown (XPTI) deliberately left interrupts enabled on two entry paths; one
    unconditionally, and one conditionally on whether XPTI was active. As BTC/SRSO and Meltdown affect
    different CPU vendors, the mitigations are not active together by default. Therefore, there is a race
    condition whereby a malicious PV guest can bypass BTC/SRSO protections and launch a BTC/SRSO attack
    against Xen. (CVE-2023-46836)

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://bodhi.fedoraproject.org/updates/FEDORA-2023-56901a79a1");
  script_set_attribute(attribute:"solution", value:
"Update the affected xen package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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-2023-46835");

  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:"2023/11/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/11/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/11/29");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:38");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:xen");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Fedora' >!< os_release) audit(AUDIT_OS_NOT, 'Fedora');
var os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Fedora');
os_ver = os_ver[1];
if (! preg(pattern:"^38([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 38', 'Fedora ' + os_ver);

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

var pkgs = [
    {'reference':'xen-4.17.2-5.fc38', 'release':'FC38', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var reference = NULL;
  var _release = NULL;
  var sp = NULL;
  var _cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) _cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (reference && _release) {
    if (rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
  }
}

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