Oracle Linux 7 : Unbreakable Enterprise kernel (ELSA-2019-4541)

#%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-2019-4541.
##

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

if (description)
{
  script_id(122141);
  script_version("1.13");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/09/08");

  script_cve_id(
    "CVE-2018-13053",
    "CVE-2018-16882",
    "CVE-2018-17972",
    "CVE-2018-18397",
    "CVE-2019-5489"
  );
  script_xref(name:"IAVA", value:"2020-A-0325-S");

  script_name(english:"Oracle Linux 7 : Unbreakable Enterprise kernel (ELSA-2019-4541)");

  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-2019-4541 advisory.

  - The mincore() implementation in mm/mincore.c in the Linux kernel through 4.19.13 allowed local attackers
    to observe page cache access patterns of other processes on the same system, potentially allowing sniffing
    of secret information. (Fixing this affects the output of the fincore program.) Limited remote
    exploitation may be possible, as demonstrated by latency differences in accessing public files from an
    Apache HTTP Server. (CVE-2019-5489)

  - The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain
    UFFDIO_ ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file (if
    the user has read-only access to that file, and that file contains holes), related to fs/userfaultfd.c and
    mm/userfaultfd.c. (CVE-2018-18397)

  - An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel through
    4.18.11. It does not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a
    local attacker to exploit racy stack unwinding and leak kernel task stack contents. (CVE-2018-17972)

  - A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts
    when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while
    processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor
    address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash
    the host kernel resulting in DoS or potentially gain privileged access to a system. Kernel versions before
    4.14.91 and before 4.19.13 are vulnerable. (CVE-2018-16882)

  - The alarm_timer_nsleep function in kernel/time/alarmtimer.c in the Linux kernel through 4.17.3 has an
    integer overflow via a large relative timeout because ktime_add_safe is not used. (CVE-2018-13053)

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-2019-4541.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:L/UI:N/S:C/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-2018-16882");

  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:"2018/06/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/02/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/02/13");

  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:kernel-uek");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-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_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2019-2021 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);

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 = ['4.14.35-1844.2.5.el7uek'];
  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-2019-4541');
    }
  }
  __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 = '4.14';
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':'kernel-uek-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-4.14.35'},
    {'reference':'kernel-uek-4.14.35-1844.2.5.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-4.14.35'},
    {'reference':'kernel-uek-debug-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-4.14.35'},
    {'reference':'kernel-uek-debug-4.14.35-1844.2.5.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-4.14.35'},
    {'reference':'kernel-uek-debug-devel-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-4.14.35'},
    {'reference':'kernel-uek-debug-devel-4.14.35-1844.2.5.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-4.14.35'},
    {'reference':'kernel-uek-devel-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-4.14.35'},
    {'reference':'kernel-uek-devel-4.14.35-1844.2.5.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-4.14.35'},
    {'reference':'kernel-uek-doc-4.14.35-1844.2.5.el7uek', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-4.14.35'},
    {'reference':'kernel-uek-headers-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-headers-4.14.35'},
    {'reference':'kernel-uek-tools-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-4.14.35'},
    {'reference':'kernel-uek-tools-4.14.35-1844.2.5.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-4.14.35'},
    {'reference':'kernel-uek-tools-libs-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-libs-4.14.35'},
    {'reference':'kernel-uek-tools-libs-devel-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-libs-devel-4.14.35'},
    {'reference':'perf-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python-perf-4.14.35-1844.2.5.el7uek', 'cpu':'aarch64', '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, 'kernel-uek / kernel-uek-debug / kernel-uek-debug-devel / etc');
}