RHEL 7 : kernel (RHSA-2018:2216) (Spectre)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:2216. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(111148);
  script_version("1.10");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/04/15");

  script_cve_id("CVE-2018-3639");
  script_xref(name:"RHSA", value:"2018:2216");

  script_name(english:"RHEL 7 : kernel (RHSA-2018:2216) (Spectre)");
  script_summary(english:"Checks the rpm output for the updated packages");

  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 7.2
Advanced Update Support, Red Hat Enterprise Linux 7.2 Telco Extended
Update Support, and Red Hat Enterprise Linux 7.2 Update Services for
SAP Solutions.

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) :

* An industry-wide issue was found in the way many modern
microprocessor designs have implemented speculative execution of Load
& Store instructions (a commonly used performance optimization). It
relies on the presence of a precisely-defined instruction sequence in
the privileged code as well as the fact that memory read from address
to which a recent memory write has occurred may see an older value and
subsequently cause an update 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
read privileged memory by conducting targeted cache side-channel
attacks. (CVE-2018-3639, x86 AMD)

Red Hat would like to thank Ken Johnson (Microsoft Security Response
Center) and Jann Horn (Google Project Zero) for reporting this issue.

Bug Fix(es) :

* When switching from the indirect branch speculation (IBRS) feature
to the retpolines feature, the IBRS state of some CPUs was sometimes
not handled correctly. Consequently, some CPUs were left with the IBRS
Model-Specific Register (MSR) bit set to 1, which could lead to
performance issues. With this update, the underlying source code has
been fixed to clear the IBRS MSR bits correctly, thus fixing the bug.
(BZ#1586145)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/vulnerabilities/ssbd"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHSA-2018:2216"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-3639"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N");
  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:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  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-abi-whitelists");
  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-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-tools-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-tools-libs-devel");
  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:7.2");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/05/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/07/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/07/18");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Red Hat Local Security Checks");

  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:"^7\.2([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Red Hat 7.2", "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-2018-3639");
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, "KSplice hotfix for RHSA-2018:2216");
  }
  else
  {
    __rpm_report = ksplice_reporting_text();
  }
}

yum_updateinfo = get_kb_item("Host/RedHat/yum-updateinfo");
if (!empty_or_null(yum_updateinfo)) 
{
  rhsa = "RHSA-2018:2216";
  yum_report = redhat_generate_yum_updateinfo_report(rhsa:rhsa);
  if (!empty_or_null(yum_report))
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_NOTE,
      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:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", reference:"kernel-abi-whitelists-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-debug-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-debug-debuginfo-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-debug-devel-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-debuginfo-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-debuginfo-common-x86_64-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-devel-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", reference:"kernel-doc-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-headers-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-tools-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-tools-debuginfo-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-tools-libs-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"kernel-tools-libs-devel-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"perf-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"perf-debuginfo-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"python-perf-3.10.0-327.71.1.el7")) flag++;
  if (rpm_check(release:"RHEL7", sp:"2", cpu:"x86_64", reference:"python-perf-debuginfo-3.10.0-327.71.1.el7")) flag++;

  if (flag)
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_NOTE,
      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-abi-whitelists / kernel-debug / etc");
  }
}