Oracle Linux 7 : kernel (ELSA-2021-0336)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2021-0336.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(146078);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/24");

  script_cve_id("CVE-2020-15436", "CVE-2020-35513");

  script_name(english:"Oracle Linux 7 : kernel (ELSA-2021-0336)");

  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 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2021-0336 advisory.

  - Use-after-free vulnerability in fs/block_dev.c in the Linux kernel before 5.8 allows local users to gain
    privileges or cause a denial of service by leveraging improper access to a certain error field.
    (CVE-2020-15436)

  - A flaw incorrect umask during file or directory modification in the Linux kernel NFS (network file system)
    functionality was found in the way user create and delete object using NFSv4.2 or newer if both
    simultaneously accessing the NFS by the other process that is not using new NFSv4.2. A user with access to
    the NFS could use this flaw to starve the resources causing denial of service. (CVE-2020-35513)

Note that Nessus has not tested for this issue 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-2021-0336.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:H/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-2020-15436");

  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:"2020/07/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/02/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/02/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:bpftool");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-abi-whitelists");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-tools-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-tools-libs-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:perf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:python-perf");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('audit.inc');
include('global_settings.inc');
include('ksplice.inc');
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 release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
var os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7', '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);
if ('x86_64' >!< cpu) audit(AUDIT_ARCH_NOT, 'x86_64', cpu);

var machine_uptrack_level = get_one_kb_item('Host/uptrack-uname-r');
if (machine_uptrack_level)
{
  var trimmed_uptrack_level = ereg_replace(string:machine_uptrack_level, pattern:"\.(x86_64|i[3-6]86|aarch64)$", replace:'');
  var fixed_uptrack_levels = ['3.10.0-1160.15.2.el7'];
  foreach var fixed_uptrack_level ( fixed_uptrack_levels ) {
    if (rpm_spec_vers_cmp(a:trimmed_uptrack_level, b:fixed_uptrack_level) >= 0)
    {
      audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for ELSA-2021-0336');
    }
  }
  __rpm_report = 'Running KSplice level of ' + trimmed_uptrack_level + ' does not meet the minimum fixed level of ' + join(fixed_uptrack_levels, sep:' / ') + ' for this advisory.\n\n';
}

var kernel_major_minor = get_kb_item('Host/uname/major_minor');
if (empty_or_null(kernel_major_minor)) exit(1, 'Unable to determine kernel major-minor level.');
var expected_kernel_major_minor = '3.10';
if (kernel_major_minor != expected_kernel_major_minor)
  audit(AUDIT_OS_NOT, 'running kernel level ' + expected_kernel_major_minor + ', it is running kernel level ' + kernel_major_minor);

var pkgs = [
    {'reference':'bpftool-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-3.10.0'},
    {'reference':'kernel-abi-whitelists-3.10.0-1160.15.2.el7', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-abi-whitelists-3.10.0'},
    {'reference':'kernel-debug-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-3.10.0'},
    {'reference':'kernel-debug-devel-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-devel-3.10.0'},
    {'reference':'kernel-devel-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-devel-3.10.0'},
    {'reference':'kernel-headers-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-headers-3.10.0'},
    {'reference':'kernel-tools-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-3.10.0'},
    {'reference':'kernel-tools-libs-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-libs-3.10.0'},
    {'reference':'kernel-tools-libs-devel-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-libs-devel-3.10.0'},
    {'reference':'perf-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python-perf-3.10.0-1160.15.2.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE}
];

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, 'bpftool / kernel / kernel-abi-whitelists / etc');
}