EulerOS Virtualization 3.0.2.2 : grub2 (EulerOS-SA-2023-1257)

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

include('compat.inc');

if (description)
{
  script_id(170821);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/18");

  script_cve_id(
    "CVE-2021-3695",
    "CVE-2021-3696",
    "CVE-2021-3981",
    "CVE-2022-28734"
  );

  script_name(english:"EulerOS Virtualization 3.0.2.2 : grub2 (EulerOS-SA-2023-1257)");

  script_set_attribute(attribute:"synopsis", value:
"The remote EulerOS Virtualization host is missing multiple security updates.");
  script_set_attribute(attribute:"description", value:
"According to the versions of the grub2 packages installed, the EulerOS Virtualization installation on the remote host is
affected by the following vulnerabilities :

  - A crafted 16-bit grayscale PNG image may lead to a out-of-bounds write in the heap area. An attacker may
    take advantage of that to cause heap data corruption or eventually arbitrary code execution and circumvent
    secure boot protections. This issue has a high complexity to be exploited as an attacker needs to perform
    some triage over the heap layout to achieve signifcant results, also the values written into the memory
    are repeated three times in a row making difficult to produce valid payloads. This flaw affects grub2
    versions prior grub-2.12. (CVE-2021-3695)

  - A heap out-of-bounds write may heppen during the handling of Huffman tables in the PNG reader. This may
    lead to data corruption in the heap space. Confidentiality, Integrity and Availablity impact may be
    considered Low as it's very complex to an attacker control the encoding and positioning of corrupted
    Huffman entries to achieve results such as arbitrary code execution and/or secure boot circumvention. This
    flaw affects grub2 versions prior grub-2.12. (CVE-2021-3696)

  - A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong
    permission set allowing non privileged users to read its content. This represents a low severity
    confidentiality issue, as those users can eventually read any encrypted passwords present in grub.cfg.
    This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no
    version with the fix is currently released. (CVE-2021-3981)

  - Out-of-bounds write when handling split HTTP headers; When handling split HTTP headers, GRUB2 HTTP code
    accidentally moves its internal data buffer point by one position. This can lead to a out-of-bound write
    further when parsing the HTTP request, writing a NULL byte past the buffer. It's conceivable that an
    attacker controlled set of packets can lead to corruption of the GRUB2's internal memory metadata.
    (CVE-2022-28734)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security
advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional
issues.");
  # https://developer.huaweicloud.com/ict/en/site-euleros/euleros/security-advisories/EulerOS-SA-2023-1257
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?62ab5f6b");
  script_set_attribute(attribute:"solution", value:
"Update the affected grub2 packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/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:H/PR:N/UI:N/S:U/C:L/I:L/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3696");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2022-28734");

  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:"2020/07/30");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/01/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/01/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-efi-x64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-efi-x64-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-efi-x64-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-pc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-pc-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-tools-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:huawei:euleros:grub2-tools-minimal");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:huawei:euleros:uvp:3.0.2.2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Huawei 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/cpu", "Host/EulerOS/release", "Host/EulerOS/rpm-list", "Host/EulerOS/uvp_version");

  exit(0);
}

include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var _release = get_kb_item("Host/EulerOS/release");
if (isnull(_release) || _release !~ "^EulerOS") audit(AUDIT_OS_NOT, "EulerOS");
var uvp = get_kb_item("Host/EulerOS/uvp_version");
if (uvp != "3.0.2.2") audit(AUDIT_OS_NOT, "EulerOS Virtualization 3.0.2.2");
if (!get_kb_item("Host/EulerOS/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$" && "aarch64" >!< cpu && "x86" >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "EulerOS", cpu);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "x86" >!< cpu) audit(AUDIT_ARCH_NOT, "i686 / x86_64", cpu);

var flag = 0;

var pkgs = [
  "grub2-2.02-0.65.2.h17",
  "grub2-common-2.02-0.65.2.h17",
  "grub2-efi-x64-2.02-0.65.2.h17",
  "grub2-efi-x64-cdboot-2.02-0.65.2",
  "grub2-efi-x64-modules-2.02-0.65.2.h17",
  "grub2-pc-2.02-0.65.2.h17",
  "grub2-pc-modules-2.02-0.65.2.h17",
  "grub2-tools-2.02-0.65.2.h17",
  "grub2-tools-extra-2.02-0.65.2.h17",
  "grub2-tools-minimal-2.02-0.65.2.h17"
];

foreach (var pkg in pkgs)
  if (rpm_check(release:"EulerOS-2.0", reference:pkg)) 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, "grub2");
}