RHEL 6 : kernel-rt (RHSA-2018:0021)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:0021. The text 
# itself is copyright (C) Red Hat, Inc.
#

include('compat.inc');

if (description)
{
  script_id(105672);
  script_version("3.19");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/06/03");

  script_cve_id("CVE-2017-5715", "CVE-2017-5753", "CVE-2017-5754");
  script_xref(name:"RHSA", value:"2018:0021");
  script_xref(name:"IAVA", value:"2018-A-0019");
  script_xref(name:"IAVA", value:"2018-A-0020");
  script_xref(name:"IAVA", value:"2018-A-0017-S");

  script_name(english:"RHEL 6 : kernel-rt (RHSA-2018:0021)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing one or more security updates for kernel-rt.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 6 host has packages installed that are affected by multiple vulnerabilities as
referenced in the RHSA-2018:0021 advisory.

    The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with
    extremely high determinism requirements.

    Security Fix(es):

    An industry-wide issue was found in the way many modern microprocessor designs have implemented
    speculative execution of instructions (a commonly used performance optimization). There are three primary
    variants of the issue which differ in the way the speculative execution can be exploited.

    Note: This issue is present in hardware and cannot be fully fixed via software update. The updated kernel
    packages provide software mitigation for this hardware issue at a cost of potential performance penalty.
    Please refer to References section for further information about this issue and the performance impact.

    In this update mitigations for x86-64 architecture are provided.

    Variant CVE-2017-5753 triggers the speculative execution by performing a bounds-check bypass. It relies on
    the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that
    memory accesses may cause allocation into the microprocessor's data cache even for speculatively executed
    instructions that never actually commit (retire). As a result, an unprivileged attacker could use this
    flaw to cross the syscall boundary and read privileged memory by conducting targeted cache side-channel
    attacks. (CVE-2017-5753, Important)

    Variant CVE-2017-5715 triggers the speculative execution by utilizing branch target injection. It relies
    on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact
    that memory accesses may cause allocation into the microprocessor's data cache even for speculatively
    executed instructions that never actually commit (retire). As a result, an unprivileged attacker could use
    this flaw to cross the syscall and guest/host boundaries and read privileged memory by conducting targeted
    cache side-channel attacks. (CVE-2017-5715, Important)

    Variant CVE-2017-5754 relies on the fact that, on impacted microprocessors, during speculative execution
    of instruction permission faults, exception generation triggered by a faulting access is suppressed until
    the retirement of the whole instruction block. In a combination with the fact that memory accesses may
    populate the cache even when the block is being dropped and never committed (executed), an unprivileged
    local attacker could use this flaw to read privileged (kernel space) memory by conducting targeted cache
    side-channel attacks. (CVE-2017-5754, Important)

    Note: CVE-2017-5754 affects Intel x86-64 microprocessors. AMD x86-64 microprocessors are not affected by
    this issue.

    Red Hat would like to thank Google Project Zero for reporting these issues.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://access.redhat.com/security/data/csaf/v2/advisories/2018/rhsa-2018_0021.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4b1c7490");
  # https://access.redhat.com/security/vulnerabilities/speculativeexecution
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?892ef523");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/updates/classification/#important");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=1519778");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=1519780");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=1519781");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2018:0021");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/CVE-2017-5715");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/CVE-2017-5753");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/CVE-2017-5754");
  script_set_attribute(attribute:"solution", value:
"Update the RHEL kernel-rt package based on the guidance in RHSA-2018:0021.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:H/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:H/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-5754");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_malware", value:"true");
  script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
  script_set_attribute(attribute:"canvas_package", value:"CANVAS");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_cwe_id(200);
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/01/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/01/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/01/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-firmware");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-trace-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-vanilla-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Red Hat Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2018-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('rpm.inc');
include('rhel.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/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'ge', os_version: os_ver, rhel_version: '6')) audit(AUDIT_OS_NOT, 'Red Hat 6.x', 'Red Hat ' + 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$" && 's390' >!< cpu && 'aarch64' >!< cpu && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  rm_kb_item(name:'Host/uptrack-uname-r');
  var cve_list = make_list('CVE-2017-5715', 'CVE-2017-5753', 'CVE-2017-5754');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for RHSA-2018:0021');
  }
  else
  {
    __rpm_report = ksplice_reporting_text();
  }
}

var constraints = [
  {
    'repo_relative_urls': [
      'content/dist/rhel/server/6/6Server/x86_64/mrg-g-execute/2/debug',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-g-execute/2/os',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-g-execute/2/source/SRPMS',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-g/2/debug',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-g/2/os',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-g/2/source/SRPMS',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-m/2/debug',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-m/2/os',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-m/2/source/SRPMS',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-mgmt/2/debug',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-mgmt/2/os',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-mgmt/2/source/SRPMS',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-r/2/debug',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-r/2/os',
      'content/dist/rhel/server/6/6Server/x86_64/mrg-r/2/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'kernel-rt-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-debug-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-debug-devel-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-devel-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-doc-3.10.0-693.11.1.rt56.606.el6rt', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-firmware-3.10.0-693.11.1.rt56.606.el6rt', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-trace-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-trace-devel-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-vanilla-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'},
      {'reference':'kernel-rt-vanilla-devel-3.10.0-693.11.1.rt56.606.el6rt', 'cpu':'x86_64', 'release':'6', 'el_string':'el6rt', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1', 'exists_check':'mrg-release'}
    ]
  }
];

var applicable_repo_urls = rhel_determine_applicable_repository_urls(constraints:constraints);
if(applicable_repo_urls == RHEL_REPOS_NO_OVERLAP_MESSAGE) exit(0, RHEL_REPO_NOT_ENABLED);

var flag = 0;
foreach var constraint_array ( constraints ) {
  var repo_relative_urls = NULL;
  if (!empty_or_null(constraint_array['repo_relative_urls'])) repo_relative_urls = constraint_array['repo_relative_urls'];
  foreach var pkg ( constraint_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;
    var cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        _release &&
        rhel_decide_repo_relative_url_check(required_repo_url_list:repo_relative_urls) &&
        (applicable_repo_urls || (!exists_check || 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, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = NULL;
  if (isnull(applicable_repo_urls) || !applicable_repo_urls) extra = rpm_report_get() + redhat_report_repo_caveat();
  else extra = rpm_report_get();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : extra
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'kernel-rt / kernel-rt-debug / kernel-rt-debug-devel / etc');
}