Oracle Linux 9 : grub2 (ELSA-2023-12019)

2023-01-1200:00:00

www.tenable.com

oracle linux 9

grub2

elsa-2023-12019

unicode sequences

buffer overflow

font code

secure boot mechanism

EPSS

0.001

Percentile

32.6%

JSON

The remote Oracle Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2023-12019 advisory.

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)
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)

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 Oracle Linux Security Advisory ELSA-2023-12019.
##

include('compat.inc');

if (description)
{
  script_id(169998);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/09/15");

  script_cve_id("CVE-2022-2601", "CVE-2022-3775");

  script_name(english:"Oracle Linux 9 : grub2 (ELSA-2023-12019)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2023-12019 advisory.

  - 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)

  - 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)

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://linux.oracle.com/errata/ELSA-2023-12019.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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:"2023/01/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/01/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-aa64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-aa64-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-aa64-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-x64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-x64-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-efi-x64-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-pc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-pc-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-tools-efi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-tools-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:grub2-tools-minimal");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

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

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

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_release = get_kb_item("Host/RedHat/release");
if (isnull(os_release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:os_release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^9([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 9', 'Oracle Linux ' + 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$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);

var pkgs = [
    {'reference':'grub2-common-2.06-46.0.4.el9', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-modules-2.06-46.0.4.el9', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-modules-2.06-46.0.4.el9', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-pc-modules-2.06-46.0.4.el9', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-2.06-46.0.4.el9', 'cpu':'aarch64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-cdboot-2.06-46.0.4.el9', 'cpu':'aarch64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-2.06-46.0.4.el9', 'cpu':'aarch64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-extra-2.06-46.0.4.el9', 'cpu':'aarch64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-minimal-2.06-46.0.4.el9', 'cpu':'aarch64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-2.06-46.0.4.el9', 'cpu':'x86_64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-cdboot-2.06-46.0.4.el9', 'cpu':'x86_64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-pc-2.06-46.0.4.el9', 'cpu':'x86_64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-2.06-46.0.4.el9', 'cpu':'x86_64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-efi-2.06-46.0.4.el9', 'cpu':'x86_64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-extra-2.06-46.0.4.el9', 'cpu':'x86_64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-minimal-2.06-46.0.4.el9', 'cpu':'x86_64', 'release':'9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
];

var flag = 0;
foreach var 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;
  var exists_check = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = 'EL' + 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 (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && _release) {
    if (exists_check) {
        if (rpm_exists(release:_release, rpm:exists_check) && 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++;
    } else {
        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, 'grub2-common / grub2-efi-aa64 / grub2-efi-aa64-cdboot / etc');
}