Ubuntu 18.04 ESM / 20.04 LTS : Linux kernel vulnerabilities (USN-6317-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-6317-1. 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(180257);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");

  script_cve_id(
    "CVE-2022-40982",
    "CVE-2023-3609",
    "CVE-2023-3611",
    "CVE-2023-3776",
    "CVE-2023-20593"
  );
  script_xref(name:"USN", value:"6317-1");

  script_name(english:"Ubuntu 18.04 ESM / 20.04 LTS : Linux kernel vulnerabilities (USN-6317-1)");

  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-6317-1 advisory.

  - Information exposure through microarchitectural state after transient execution in certain vector
    execution units for some Intel(R) Processors may allow an authenticated user to potentially enable
    information disclosure via local access. (CVE-2022-40982)

  - An issue in Zen 2 CPUs, under specific microarchitectural circumstances, may allow an attacker to
    potentially access sensitive information. (CVE-2023-20593)

  - A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to
    achieve local privilege escalation. If tcf_change_indev() fails, u32_set_parms() will immediately return
    an error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can
    control the reference counter and set it to zero, they can cause the reference to be freed, leading to a
    use-after-free vulnerability. We recommend upgrading past commit 04c55383fa5689357bcdd2c8036725a55ed632bc.
    (CVE-2023-3609)

  - An out-of-bounds write vulnerability in the Linux kernel's net/sched: sch_qfq component can be exploited
    to achieve local privilege escalation. The qfq_change_agg() function in net/sched/sch_qfq.c allows an out-
    of-bounds write because lmax is updated according to packet sizes without bounds checks. We recommend
    upgrading past commit 3e337087c3b5805fe0b8a46ba622a962880b5d64. (CVE-2023-3611)

  - A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to
    achieve local privilege escalation. If tcf_change_indev() fails, fw_set_parms() will immediately return an
    error after incrementing or decrementing the reference counter in tcf_bind_filter(). If an attacker can
    control the reference counter and set it to zero, they can cause the reference to be freed, leading to a
    use-after-free vulnerability. We recommend upgrading past commit 0323bce598eea038714f941ce2b22541c46d488f.
    (CVE-2023-3776)

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-6317-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/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:L/UI:N/S:U/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-2023-3776");

  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:"2023/07/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/08/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/08/29");

  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-5.4.0-1028-xilinx-zynqmp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1097-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1107-oracle");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1108-aws");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-1111-gcp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-159-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-159-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.4.0-159-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", "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 kernel_mappings = {
  '18.04': {
    '5.4.0': {
      'generic': '5.4.0-159',
      'generic-lpae': '5.4.0-159',
      'lowlatency': '5.4.0-159',
      'aws': '5.4.0-1108'
    }
  },
  '20.04': {
    '5.4.0': {
      'generic': '5.4.0-159',
      'generic-lpae': '5.4.0-159',
      'lowlatency': '5.4.0-159',
      'xilinx-zynqmp': '5.4.0-1028',
      'kvm': '5.4.0-1097',
      'oracle': '5.4.0-1107',
      'aws': '5.4.0-1108',
      'gcp': '5.4.0-1111'
    }
  }
};

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 (deb_ver_cmp(ver1:host_kernel_release, ver2:kernel_fixed_version) < 0)
{
  extra = 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-6317-1');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2022-40982', 'CVE-2023-3609', 'CVE-2023-3611', 'CVE-2023-3776', 'CVE-2023-20593');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-6317-1');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}