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nessusThis script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.FEDORA_2022-F86E203BAF.NASL
HistoryDec 22, 2022 - 12:00 a.m.

Fedora 36 : 1:grub2 (2022-f86e203baf)

2022-12-2200:00:00
This script is Copyright (C) 2022-2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
5

8.6 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

0.001 Low

EPSS

Percentile

26.4%

The remote Fedora 36 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2022-f86e203baf advisory.

  • A buffer overflow was found in grub_font_construct_glyph(). A malicious crafted pf2 font can lead to an overflow when calculating the max_glyph_size value, allocating a smaller than needed buffer for the glyph, this further leads to a buffer overflow and a heap based out-of-bounds write. An attacker may use this vulnerability to circumvent the secure boot mechanism. (CVE-2022-2601)

  • When rendering certain unicode sequences, grub2’s font code doesn’t proper validate if the informed glyph’s width and height is constrained within bitmap size. As consequence an attacker can craft an input which will lead to a out-of-bounds write into grub2’s heap, leading to memory corruption and availability issues. Although complex, arbitrary code execution could not be discarded. (CVE-2022-3775)

Note that Nessus has not tested for these issues but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##
# The descriptive text and package checks in this plugin were
# extracted from Fedora Security Advisory FEDORA-2022-f86e203baf
#

include('compat.inc');

if (description)
{
  script_id(169142);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/09/12");

  script_cve_id("CVE-2022-2601", "CVE-2022-3775");
  script_xref(name:"FEDORA", value:"2022-f86e203baf");

  script_name(english:"Fedora 36 : 1:grub2 (2022-f86e203baf)");

  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 36 host has a package installed that is affected by multiple vulnerabilities as referenced in the
FEDORA-2022-f86e203baf advisory.

  - A buffer overflow was found in grub_font_construct_glyph(). A malicious crafted pf2 font can lead to an
    overflow when calculating the max_glyph_size value, allocating a smaller than needed buffer for the glyph,
    this further leads to a buffer overflow and a heap based out-of-bounds write. An attacker may use this
    vulnerability to circumvent the secure boot mechanism. (CVE-2022-2601)

  - When rendering certain unicode sequences, grub2's font code doesn't proper validate if the informed
    glyph's width and height is constrained within bitmap size. As consequence an attacker can craft an input
    which will lead to a out-of-bounds write into grub2's heap, leading to memory corruption and availability
    issues. Although complex, arbitrary code execution could not be discarded. (CVE-2022-3775)

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-2022-f86e203baf");
  script_set_attribute(attribute:"solution", value:
"Update the affected 1:grub2 package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2022-2601");

  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:"2022/11/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/11/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/12/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:36");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:fedoraproject:fedora:grub2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022-2023 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:"^36([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Fedora 36', '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':'grub2-2.06-57.fc36', 'release':'FC36', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
];

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_HOLE,
      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, '1:grub2');
}
VendorProductVersionCPE
fedoraprojectfedora36cpe:/o:fedoraproject:fedora:36
fedoraprojectfedoragrub2p-cpe:/a:fedoraproject:fedora:grub2

8.6 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

0.001 Low

EPSS

Percentile

26.4%