Ubuntu 18.04 ESM / 20.04 LTS : Linux kernel vulnerabilities (USN-6417-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-6417-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(182578);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  script_cve_id(
    "CVE-2021-4001",
    "CVE-2023-1206",
    "CVE-2023-3212",
    "CVE-2023-3338",
    "CVE-2023-3863",
    "CVE-2023-4194"
  );
  script_xref(name:"USN", value:"6417-1");

  script_name(english:"Ubuntu 18.04 ESM / 20.04 LTS : Linux kernel vulnerabilities (USN-6417-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 18.04 ESM / 20.04 LTS host has a package installed that is affected by multiple vulnerabilities as
referenced in the USN-6417-1 advisory.

    It was discovered that the eBPF implementation in the Linux kernel contained a race condition around read-
    only maps. A privileged attacker could use this to modify read-only maps. (CVE-2021-4001)

    It was discovered that the IPv6 implementation in the Linux kernel contained a high rate of hash
    collisions in connection lookup table. A remote attacker could use this to cause a denial of service
    (excessive CPU consumption). (CVE-2023-1206)

    Yang Lan discovered that the GFS2 file system implementation in the Linux kernel could attempt to
    dereference a null pointer in some situations. An attacker could use this to construct a malicious GFS2
    image that, when mounted and operated on, could cause a denial of service (system crash). (CVE-2023-3212)

    Davide Ornaghi discovered that the DECnet network protocol implementation in the Linux kernel contained a
    null pointer dereference vulnerability. A remote attacker could use this to cause a denial of service
    (system crash) or possibly execute arbitrary code. Please note that kernel support for the DECnet has been
    removed to resolve this CVE. (CVE-2023-3338)

    It was discovered that the NFC implementation in the Linux kernel contained a use-after-free vulnerability
    when performing peer-to-peer communication in certain conditions. A privileged attacker could use this to
    cause a denial of service (system crash) or possibly expose sensitive information (kernel memory).
    (CVE-2023-3863)

    It was discovered that the TUN/TAP driver in the Linux kernel did not properly initialize socket data. A
    local attacker could use this to cause a denial of service (system crash). (CVE-2023-4194)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

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://ubuntu.com/security/notices/USN-6417-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:N/I:C/A:N");
  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:L/UI:N/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-4001");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2023-4194");

  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:"2022/01/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/10/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/10/05");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:esm");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1023-iot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1031-xilinx-zynqmp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1058-ibm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1072-bluefield");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1078-gkeop");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1095-raspi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1100-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1110-oracle");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1111-aws");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1115-gcp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1117-azure");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-164-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-164-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-164-lowlatency");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2023-2024 Canonical, Inc. / NASL script (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl", "ubuntu_pro_sub_detect.nasl", "linux_alt_patch_detect.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');
include('ksplice.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 18.04 / 20.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) 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, 'Ubuntu', cpu);

var ubuntu_pro_detected = get_kb_item('Host/Ubuntu/Pro/Services/esm-apps');
ubuntu_pro_detected = !empty_or_null(ubuntu_pro_detected);

var kernel_mappings = {
  '18.04': {
    '5.4.0': {
      'generic': '5.4.0-164',
      'lowlatency': '5.4.0-164',
      'ibm': '5.4.0-1058',
      'raspi': '5.4.0-1095',
      'oracle': '5.4.0-1110',
      'aws': '5.4.0-1111',
      'gcp': '5.4.0-1115',
      'azure': '5.4.0-1117'
    }
  },
  '20.04': {
    '5.4.0': {
      'generic': '5.4.0-164',
      'generic-lpae': '5.4.0-164',
      'lowlatency': '5.4.0-164',
      'iot': '5.4.0-1023',
      'xilinx-zynqmp': '5.4.0-1031',
      'ibm': '5.4.0-1058',
      'bluefield': '5.4.0-1072',
      'gkeop': '5.4.0-1078',
      'raspi': '5.4.0-1095',
      'kvm': '5.4.0-1100',
      'oracle': '5.4.0-1110',
      'aws': '5.4.0-1111',
      'gcp': '5.4.0-1115',
      'azure': '5.4.0-1117'
    }
  }
};

var host_kernel_release = get_kb_item('Host/uptrack-uname-r');
if (empty_or_null(host_kernel_release)) host_kernel_release = get_kb_item_or_exit('Host/uname-r');
var host_kernel_base_version = get_kb_item_or_exit('Host/Debian/kernel-base-version');
var host_kernel_type = get_kb_item_or_exit('Host/Debian/kernel-type');
if(empty_or_null(kernel_mappings[os_release][host_kernel_base_version][host_kernel_type])) audit(AUDIT_INST_VER_NOT_VULN, 'kernel ' + host_kernel_release);

var extra = '';
var kernel_fixed_version = kernel_mappings[os_release][host_kernel_base_version][host_kernel_type] + "-" + host_kernel_type;
if (!ubuntu_pro_detected) {
  extra += 'NOTE: This vulnerability check contains fixes that apply to packages only \n';
  extra += 'available in Ubuntu ESM repositories. Access to these package security updates \n';
  extra += 'require an Ubuntu Pro subscription.\n\n';
}
if (deb_ver_cmp(ver1:host_kernel_release, ver2:kernel_fixed_version) < 0)
{
  extra += 'Running Kernel level of ' + host_kernel_release + ' does not meet the minimum fixed level of ' + kernel_fixed_version + ' for this advisory.\n\n';
}
  else
{
  audit(AUDIT_PATCH_INSTALLED, 'Kernel package for USN-6417-1');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2021-4001', 'CVE-2023-1206', 'CVE-2023-3212', 'CVE-2023-3338', 'CVE-2023-3863', 'CVE-2023-4194');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-6417-1');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}