RHEL 6 : qemu-kvm (RHSA-2018:2162) (Spectre)

2018-07-11T00:00:00
ID REDHAT-RHSA-2018-2162.NASL
Type nessus
Reporter Tenable
Modified 2018-11-10T00:00:00

Description

An update for qemu-kvm is now available for Red Hat Enterprise Linux 6.

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.

Kernel-based Virtual Machine (KVM) is a full virtualization solution for Linux on a variety of architectures. The qemu-kvm packages provide the user-space component for running virtual machines that use KVM.

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)

Note: This is the qemu-kvm side of the CVE-2018-3639 mitigation.

  • QEMU: cirrus: OOB access when updating VGA display (CVE-2018-7858)

  • QEMU: vga: OOB read access during display update (CVE-2017-13672)

  • Qemu: Out-of-bounds read in vga_draw_text routine (CVE-2018-5683)

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 Ken Johnson (Microsoft Security Response Center) and Jann Horn (Google Project Zero) for reporting CVE-2018-3639; Ross Lagerwall (Citrix.com) for reporting CVE-2018-7858; David Buchanan for reporting CVE-2017-13672; and Jiang Xin and Lin ZheCheng for reporting CVE-2018-5683.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:2162. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(111000);
  script_version("1.2");
  script_cvs_date("Date: 2018/11/10 11:49:57");

  script_cve_id("CVE-2017-13672", "CVE-2018-3639", "CVE-2018-5683", "CVE-2018-7858");
  script_xref(name:"RHSA", value:"2018:2162");

  script_name(english:"RHEL 6 : qemu-kvm (RHSA-2018:2162) (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 qemu-kvm is now available for Red Hat Enterprise Linux
6.

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.

Kernel-based Virtual Machine (KVM) is a full virtualization solution
for Linux on a variety of architectures. The qemu-kvm packages provide
the user-space component for running virtual machines that use KVM.

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)

Note: This is the qemu-kvm side of the CVE-2018-3639 mitigation.

* QEMU: cirrus: OOB access when updating VGA display (CVE-2018-7858)

* QEMU: vga: OOB read access during display update (CVE-2017-13672)

* Qemu: Out-of-bounds read in vga_draw_text routine (CVE-2018-5683)

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 Ken Johnson (Microsoft Security Response
Center) and Jann Horn (Google Project Zero) for reporting
CVE-2018-3639; Ross Lagerwall (Citrix.com) for reporting
CVE-2018-7858; David Buchanan for reporting CVE-2017-13672; and Jiang
Xin and Lin ZheCheng for reporting CVE-2018-5683."
  );
  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-2018:2162"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2017-13672"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-3639"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-5683"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2018-7858"
  );
  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:N/A:N");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:qemu-guest-agent");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:qemu-img");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:qemu-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:qemu-kvm-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:qemu-kvm-tools");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/07/10");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/07/11");
  script_end_attributes();

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

  script_dependencies("ssh_get_info.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");

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 = eregmatch(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 (! ereg(pattern:"^6([^0-9]|$)", string:os_ver)) 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);

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);

yum_updateinfo = get_kb_item("Host/RedHat/yum-updateinfo");
if (!empty_or_null(yum_updateinfo)) 
{
  rhsa = "RHSA-2018:2162";
  yum_report = redhat_generate_yum_updateinfo_report(rhsa:rhsa);
  if (!empty_or_null(yum_report))
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      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", cpu:"i686", reference:"qemu-guest-agent-0.12.1.2-2.506.el6_10.1")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"qemu-guest-agent-0.12.1.2-2.506.el6_10.1")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"qemu-img-0.12.1.2-2.506.el6_10.1")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"qemu-kvm-0.12.1.2-2.506.el6_10.1")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"i686", reference:"qemu-kvm-debuginfo-0.12.1.2-2.506.el6_10.1")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"qemu-kvm-debuginfo-0.12.1.2-2.506.el6_10.1")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"qemu-kvm-tools-0.12.1.2-2.506.el6_10.1")) flag++;

  if (flag)
  {
    security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      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, "qemu-guest-agent / qemu-img / qemu-kvm / qemu-kvm-debuginfo / etc");
  }
}