Oracle Linux 7 / 8 : Unbreakable Enterprise kernel-container (ELSA-2021-9141)

#%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-2021-9141.
##

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

if (description)
{
  script_id(148458);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/16");

  script_cve_id(
    "CVE-2020-25639",
    "CVE-2020-27170",
    "CVE-2020-27171",
    "CVE-2020-28588",
    "CVE-2021-3444",
    "CVE-2021-27363",
    "CVE-2021-27364",
    "CVE-2021-27365"
  );

  script_name(english:"Oracle Linux 7 / 8 : Unbreakable Enterprise kernel-container (ELSA-2021-9141)");

  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 / 8 host has packages installed that are affected by multiple vulnerabilities as referenced in
the ELSA-2021-9141 advisory.

  - A NULL pointer dereference flaw was found in the Linux kernel's GPU Nouveau driver functionality in
    versions prior to 5.12-rc1 in the way the user calls ioctl DRM_IOCTL_NOUVEAU_CHANNEL_ALLOC. This flaw
    allows a local user to crash the system. (CVE-2020-25639)

  - An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c performs undesirable out-
    of-bounds speculation on pointer arithmetic, leading to side-channel attacks that defeat Spectre
    mitigations and obtain sensitive information from kernel memory, aka CID-f232326f6966. This affects
    pointer types that do not define a ptr_limit. (CVE-2020-27170)

  - An issue was discovered in the Linux kernel before 5.11.8. kernel/bpf/verifier.c has an off-by-one error
    (with a resultant integer underflow) affecting out-of-bounds speculation on pointer arithmetic, leading to
    side-channel attacks that defeat Spectre mitigations and obtain sensitive information from kernel memory,
    aka CID-10d2bb2e6b1d. (CVE-2020-27171)

  - An information disclosure vulnerability exists in the /proc/pid/syscall functionality of Linux Kernel 5.1
    Stable and 5.4.66. More specifically, this issue has been introduced in v5.1-rc4 (commit
    631b7abacd02b88f4b0795c08b54ad4fc3e7c7c0) and is still present in v5.10-rc4, so it's likely that all
    versions in between are affected. An attacker can read /proc/pid/syscall to trigger this vulnerability,
    which leads to the kernel leaking memory contents. (CVE-2020-28588)

  - The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when
    the source register was known to be 0. A local attacker with the ability to load bpf programs could use
    this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and
    possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in
    the upstream kernel in commit 9b00f1b78809 (bpf: Fix truncation handling for mod32 dst reg wrt zero) and
    in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101. (CVE-2021-3444)

  - An issue was discovered in the Linux kernel through 5.11.3. A kernel pointer leak can be used to determine
    the address of the iscsi_transport structure. When an iSCSI transport is registered with the iSCSI
    subsystem, the transport's handle is available to unprivileged users via the sysfs file system, at
    /sys/class/iscsi_transport/$TRANSPORT_NAME/handle. When read, the show_transport_handle function (in
    drivers/scsi/scsi_transport_iscsi.c) is called, which leaks the handle. This handle is actually the
    pointer to an iscsi_transport struct in the kernel module's global variables. (CVE-2021-27363)

  - An issue was discovered in the Linux kernel through 5.11.3. drivers/scsi/scsi_transport_iscsi.c is
    adversely affected by the ability of an unprivileged user to craft Netlink messages. (CVE-2021-27364)

  - An issue was discovered in the Linux kernel through 5.11.3. Certain iSCSI data structures do not have
    appropriate length constraints or checks, and can exceed the PAGE_SIZE value. An unprivileged user can
    send a Netlink message that is associated with iSCSI, and has a length up to the maximum length of a
    Netlink message. (CVE-2021-27365)

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://linux.oracle.com/errata/ELSA-2021-9141.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel-uek-container and / or kernel-uek-container-debug packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  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-2021-3444");

  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:"2021/03/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/03/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/04/13");

  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:"cpe:/o:oracle:linux:8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-container");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-container-debug");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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('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 os_release = get_kb_item("Host/RedHat/release");
if (isnull(os_release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:os_release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^(7|8)([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7 / 8', '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 = ['5.4.17-2102.200.13.el7', '5.4.17-2102.200.13.el8'];
  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-2021-9141');
    }
  }
  __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 = '5.4';
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-container-5.4.17-2102.200.13.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-5.4.17'},
    {'reference':'kernel-uek-container-debug-5.4.17-2102.200.13.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-debug-5.4.17'},
    {'reference':'kernel-uek-container-5.4.17-2102.200.13.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-5.4.17'},
    {'reference':'kernel-uek-container-debug-5.4.17-2102.200.13.el8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-container-debug-5.4.17'}
];

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_WARNING,
      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-container / kernel-uek-container-debug');
}