RHEL 6 : kernel (RHSA-2018:2791)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:2791. The text 
# itself is copyright (C) Red Hat, Inc.
#

include('compat.inc');

if (description)
{
  script_id(117783);
  script_version("1.10");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/02/25");

  script_cve_id("CVE-2018-5390", "CVE-2018-5391", "CVE-2018-10675");
  script_xref(name:"RHSA", value:"2018:2791");

  script_name(english:"RHEL 6 : kernel (RHSA-2018:2791)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"An update for kernel is now available for Red Hat Enterprise Linux 6.4
Advanced Update Support.

Red Hat Product Security has rated this update as having a security
impact of Important. A Common Vulnerability Scoring System (CVSS) base
score, which gives a detailed severity rating, is available for each
vulnerability from the CVE link(s) in the References section.

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

Security Fix(es) :

* A flaw named SegmentSmack was found in the way the Linux kernel
handled specially crafted TCP packets. A remote attacker could use
this flaw to trigger time and calculation expensive calls to
tcp_collapse_ofo_queue() and tcp_prune_ofo_queue() functions by
sending specially modified packets within ongoing TCP sessions which
could lead to a CPU saturation and hence a denial of service on the
system. Maintaining the denial of service condition requires
continuous two-way TCP sessions to a reachable open port, thus the
attacks cannot be performed using spoofed IP addresses.
(CVE-2018-5390)

* A flaw named FragmentSmack was found in the way the Linux kernel
handled reassembly of fragmented IPv4 and IPv6 packets. A remote
attacker could use this flaw to trigger time and calculation expensive
fragment reassembly algorithm by sending specially crafted packets
which could lead to a CPU saturation and hence a denial of service on
the system. (CVE-2018-5391)

* kernel: mm: use-after-free in do_get_mempolicy function allows local
DoS or other unspecified impact (CVE-2018-10675)

For more details about the security issue(s), including the impact, a
CVSS score, and other related information, refer to the CVE page(s)
listed in the References section.

Red Hat would like to thank Juha-Matti Tilli (Aalto University -
Department of Communications and Networking and Nokia Bell Labs) for
reporting CVE-2018-5390 and CVE-2018-5391.

Bug Fix(es) :

* After updating the system to prevent the L1 Terminal Fault (L1TF)
vulnerability, only one thread was detected on systems that offer
processing of two threads on a single processor core. With this
update, the '__max_smt_threads()' function has been fixed. As a
result, both threads are now detected correctly in the described
situation. (BZ#1625330)");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2018:2791");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2018-5390");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2018-5391");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2018-10675");
  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:U/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:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-10675");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/05/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/09/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/09/27");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-debug-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-debuginfo-common-x86_64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-firmware");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:perf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:perf-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:python-perf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:python-perf-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6.4");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2018-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("rpm.inc");
include("ksplice.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Red Hat" >!< release) audit(AUDIT_OS_NOT, "Red Hat");
os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Red Hat");
os_ver = os_ver[1];
if (! preg(pattern:"^6\.4([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Red Hat 6.4", "Red Hat " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$" && "s390" >!< 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");
  cve_list = make_list("CVE-2018-10675", "CVE-2018-5390", "CVE-2018-5391");
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "KSplice hotfix for RHSA-2018:2791");
  }
  else
  {
    __rpm_report = ksplice_reporting_text();
  }
}

yum_updateinfo = get_kb_item("Host/RedHat/yum-updateinfo");
if (!empty_or_null(yum_updateinfo)) 
{
  rhsa = "RHSA-2018:2791";
  yum_report = redhat_generate_yum_updateinfo_report(rhsa:rhsa);
  if (!empty_or_null(yum_report))
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : yum_report 
    );
    exit(0);
  }
  else
  {
    audit_message = "affected by Red Hat security advisory " + rhsa;
    audit(AUDIT_OS_NOT, audit_message);
  }
}
else
{
  flag = 0;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-debug-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-debug-debuginfo-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-debug-devel-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-debuginfo-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-debuginfo-common-x86_64-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-devel-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", reference:"kernel-doc-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", reference:"kernel-firmware-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"kernel-headers-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"perf-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"perf-debuginfo-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"python-perf-2.6.32-358.93.1.el6")) flag++;
  if (rpm_check(release:"RHEL6", sp:"4", cpu:"x86_64", reference:"python-perf-debuginfo-2.6.32-358.93.1.el6")) flag++;

  if (flag)
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get() + redhat_report_package_caveat()
    );
    exit(0);
  }
  else
  {
    tested = pkg_tests_get();
    if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
    else audit(AUDIT_PACKAGE_NOT_INSTALLED, "kernel / kernel-debug / kernel-debug-debuginfo / kernel-debug-devel / etc");
  }
}