Oracle Linux 6 : kernel (ELSA-2019-2473)

#%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-2019-2473.
##

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

if (description)
{
  script_id(127982);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/09/08");

  script_cve_id(
    "CVE-2017-17805",
    "CVE-2018-17972",
    "CVE-2019-1125",
    "CVE-2019-5489"
  );
  script_xref(name:"RHSA", value:"2019:2473");
  script_xref(name:"IAVA", value:"2020-A-0325-S");

  script_name(english:"Oracle Linux 6 : kernel (ELSA-2019-2473)");

  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 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2019-2473 advisory.

  - The Salsa20 encryption algorithm in the Linux kernel before 4.14.8 does not correctly handle zero-length
    inputs, allowing a local attacker able to use the AF_ALG-based skcipher interface
    (CONFIG_CRYPTO_USER_API_SKCIPHER) to cause a denial of service (uninitialized-memory free and kernel
    crash) or have unspecified other impact by executing a crafted sequence of system calls that use the
    blkcipher_walk API. Both the generic implementation (crypto/salsa20_generic.c) and x86 implementation
    (arch/x86/crypto/salsa20_glue.c) of Salsa20 were vulnerable. (CVE-2017-17805)

  - 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)

  - 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)

  - An information disclosure vulnerability exists when certain central processing units (CPU) speculatively
    access memory, aka 'Windows Kernel Information Disclosure Vulnerability'. This CVE ID is unique from
    CVE-2019-1071, CVE-2019-1073. (CVE-2019-1125)

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-2019-2473.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: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-2017-17805");

  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:"2017/12/20");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/08/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/08/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:6");
  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-firmware");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-headers");
  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:"^6([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 6', '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 = ['2.6.32-754.18.2.el6'];
  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-2019-2473');
    }
  }
  __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 = '2.6';
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-2.6.32-754.18.2.el6', 'cpu':'i686', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-2.6.32'},
    {'reference':'kernel-2.6.32-754.18.2.el6', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-2.6.32'},
    {'reference':'kernel-abi-whitelists-2.6.32-754.18.2.el6', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-abi-whitelists-2.6.32'},
    {'reference':'kernel-debug-2.6.32-754.18.2.el6', 'cpu':'i686', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-2.6.32'},
    {'reference':'kernel-debug-2.6.32-754.18.2.el6', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-2.6.32'},
    {'reference':'kernel-debug-devel-2.6.32-754.18.2.el6', 'cpu':'i686', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-devel-2.6.32'},
    {'reference':'kernel-debug-devel-2.6.32-754.18.2.el6', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-devel-2.6.32'},
    {'reference':'kernel-devel-2.6.32-754.18.2.el6', 'cpu':'i686', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-devel-2.6.32'},
    {'reference':'kernel-devel-2.6.32-754.18.2.el6', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-devel-2.6.32'},
    {'reference':'kernel-firmware-2.6.32-754.18.2.el6', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-firmware-2.6.32'},
    {'reference':'kernel-headers-2.6.32-754.18.2.el6', 'cpu':'i686', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-headers-2.6.32'},
    {'reference':'kernel-headers-2.6.32-754.18.2.el6', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-headers-2.6.32'},
    {'reference':'perf-2.6.32-754.18.2.el6', 'cpu':'i686', 'release':'6', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-2.6.32-754.18.2.el6', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python-perf-2.6.32-754.18.2.el6', 'cpu':'i686', 'release':'6', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python-perf-2.6.32-754.18.2.el6', 'cpu':'x86_64', 'release':'6', '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 / kernel-abi-whitelists / kernel-debug / etc');
}