Ubuntu 16.04 ESM : Linux kernel vulnerabilities (USN-6221-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-6221-1. 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(178649);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");

  script_cve_id(
    "CVE-2021-3753",
    "CVE-2021-20321",
    "CVE-2022-1184",
    "CVE-2022-26373",
    "CVE-2022-29901",
    "CVE-2023-1990",
    "CVE-2023-3111"
  );
  script_xref(name:"USN", value:"6221-1");

  script_name(english:"Ubuntu 16.04 ESM : Linux kernel vulnerabilities (USN-6221-1)");

  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 16.04 ESM host has a package installed that is affected by multiple vulnerabilities as referenced in
the USN-6221-1 advisory.

  - A race condition accessing file object in the Linux kernel OverlayFS subsystem was found in the way users
    do rename in specific way with OverlayFS. A local user could use this flaw to crash the system.
    (CVE-2021-20321)

  - A race problem was seen in the vt_k_ioctl in drivers/tty/vt/vt_ioctl.c in the Linux kernel, which may
    cause an out of bounds read in vt as the write access to vc_mode is not protected by lock-in vt_ioctl
    (KDSETMDE). The highest threat from this vulnerability is to data confidentiality. (CVE-2021-3753)

  - A use-after-free flaw was found in fs/ext4/namei.c:dx_insert_block() in the Linux kernel's filesystem sub-
    component. This flaw allows a local attacker with a user privilege to cause a denial of service.
    (CVE-2022-1184)

  - Non-transparent sharing of return predictor targets between contexts in some Intel(R) Processors may allow
    an authorized user to potentially enable information disclosure via local access. (CVE-2022-26373)

  - Intel microprocessor generations 6 to 8 are affected by a new Spectre variant that is able to bypass their
    retpoline mitigation in the kernel to leak arbitrary data. An attacker with unprivileged user access can
    hijack return instructions to achieve arbitrary speculative code execution under certain
    microarchitecture-dependent conditions. (CVE-2022-29901)

  - A use-after-free flaw was found in ndlc_remove in drivers/nfc/st-nci/ndlc.c in the Linux Kernel. This flaw
    could allow an attacker to crash the system due to a race problem. (CVE-2023-1990)

  - A use after free vulnerability was found in prepare_to_relocate in fs/btrfs/relocation.c in btrfs in the
    Linux Kernel. This possible flaw can be triggered by calling btrfs_ioctl_balance() before calling
    btrfs_ioctl_defrag(). (CVE-2023-3111)

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-6221-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:P/I:N/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: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-2022-29901");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2023-3111");

  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:"2021/09/30");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/07/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/07/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:esm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-1121-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-1158-aws");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-242-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.4.0-242-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 (! ('16.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04', '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 = {
  '16.04': {
    '4.4.0': {
      'generic': '4.4.0-242',
      'lowlatency': '4.4.0-242',
      'kvm': '4.4.0-1121',
      'aws': '4.4.0-1158'
    }
  }
};

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-6221-1');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2021-3753', 'CVE-2021-20321', 'CVE-2022-1184', 'CVE-2022-26373', 'CVE-2022-29901', 'CVE-2023-1990', 'CVE-2023-3111');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-6221-1');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_NOTE,
    extra      : extra
  );
  exit(0);
}