Oracle Linux 6 : kernel (ELSA-2018-0008) (Meltdown) (Spectre)

2018-01-05T00:00:00
ID ORACLELINUX_ELSA-2018-0008.NASL
Type nessus
Reporter Tenable
Modified 2018-02-02T00:00:00

Description

From Red Hat Security Advisory 2018:0008 :

An update for kernel 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.

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 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.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory RHSA-2018:0008 and 
# Oracle Linux Security Advisory ELSA-2018-0008 respectively.
#

if (NASL_LEVEL < 3000) exit(0);

include("compat.inc");

if (description)
{
  script_id(105599);
  script_version("$Revision: 3.8 $");
  script_cvs_date("$Date: 2018/02/02 16:15:51 $");

  script_cve_id("CVE-2017-5715", "CVE-2017-5753", "CVE-2017-5754");
  script_osvdb_id(171888, 171894, 171897);
  script_xref(name:"RHSA", value:"2018:0008");
  script_xref(name:"IAVA", value:"2018-A-0019");
  script_xref(name:"IAVA", value:"2018-A-0020");

  script_name(english:"Oracle Linux 6 : kernel (ELSA-2018-0008) (Meltdown) (Spectre)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Oracle Linux host is missing one or more security updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"From Red Hat Security Advisory 2018:0008 :

An update for kernel 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.

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 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."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://oss.oracle.com/pipermail/el-errata/2018-January/007436.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected kernel packages."
  );
  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:F/RL:ND/RC:ND");
  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:F/RL:X/RC:X");
  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:"plugin_type", value:"local");
  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-doc");
  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:"cpe", value:"cpe:/o:oracle:linux:6");

  script_set_attribute(attribute:"patch_publication_date", value:"2018/01/04");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/01/05");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2018 Tenable Network Security, Inc.");
  script_family(english:"Oracle Linux Local Security Checks");

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

  exit(0);
}


include("audit.inc");
include("global_settings.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");
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !eregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, "Oracle Linux");
os_ver = eregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Oracle Linux");
os_ver = os_ver[1];
if (! ereg(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);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Oracle Linux", cpu);

flag = 0;
if (rpm_exists(release:"EL6", rpm:"kernel-2.6.32") && rpm_check(release:"EL6", reference:"kernel-2.6.32-696.18.7.el6")) flag++;
if (rpm_exists(release:"EL6", rpm:"kernel-abi-whitelists-2.6.32") && rpm_check(release:"EL6", reference:"kernel-abi-whitelists-2.6.32-696.18.7.el6")) flag++;
if (rpm_exists(release:"EL6", rpm:"kernel-debug-2.6.32") && rpm_check(release:"EL6", reference:"kernel-debug-2.6.32-696.18.7.el6")) flag++;
if (rpm_exists(release:"EL6", rpm:"kernel-debug-devel-2.6.32") && rpm_check(release:"EL6", reference:"kernel-debug-devel-2.6.32-696.18.7.el6")) flag++;
if (rpm_exists(release:"EL6", rpm:"kernel-devel-2.6.32") && rpm_check(release:"EL6", reference:"kernel-devel-2.6.32-696.18.7.el6")) flag++;
if (rpm_exists(release:"EL6", rpm:"kernel-doc-2.6.32") && rpm_check(release:"EL6", reference:"kernel-doc-2.6.32-696.18.7.el6")) flag++;
if (rpm_exists(release:"EL6", rpm:"kernel-firmware-2.6.32") && rpm_check(release:"EL6", reference:"kernel-firmware-2.6.32-696.18.7.el6")) flag++;
if (rpm_exists(release:"EL6", rpm:"kernel-headers-2.6.32") && rpm_check(release:"EL6", reference:"kernel-headers-2.6.32-696.18.7.el6")) flag++;
if (rpm_check(release:"EL6", reference:"perf-2.6.32-696.18.7.el6")) flag++;
if (rpm_check(release:"EL6", cpu:"x86_64", reference:"python-perf-2.6.32-696.18.7.el6")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "affected kernel");
}