RHEL 6 : MRG (RHSA-2016:2107) (Dirty COW)

2016-10-27T00:00:00
ID REDHAT-RHSA-2016-2107.NASL
Type nessus
Reporter Tenable
Modified 2018-11-10T00:00:00

Description

An update for kernel-rt is now available for Red Hat Enterprise MRG 2.5.

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

Security Fix(es) :

  • A race condition was found in the way the Linux kernel's memory subsystem handled the copy-on-write (COW) breakage of private read-only memory mappings. An unprivileged, local user could use this flaw to gain write access to otherwise read-only memory mappings and thus increase their privileges on the system. (CVE-2016-5195, Important)

  • Linux kernel built with the 802.1Q/802.1ad VLAN(CONFIG_VLAN_8021Q) OR Virtual eXtensible Local Area Network(CONFIG_VXLAN) with Transparent Ethernet Bridging(TEB) GRO support, is vulnerable to a stack overflow issue. It could occur while receiving large packets via GRO path; As an unlimited recursion could unfold in both VLAN and TEB modules, leading to a stack corruption in the kernel. (CVE-2016-7039, Important)

Red Hat would like to thank Phil Oester for reporting CVE-2016-5195.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2016:2107. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(94315);
  script_version("2.18");
  script_cvs_date("Date: 2018/11/10 11:49:55");

  script_cve_id("CVE-2016-5195", "CVE-2016-7039", "CVE-2016-8666");
  script_xref(name:"RHSA", value:"2016:2107");
  script_xref(name:"IAVA", value:"2016-A-0306");

  script_name(english:"RHEL 6 : MRG (RHSA-2016:2107) (Dirty COW)");
  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-rt is now available for Red Hat Enterprise MRG
2.5.

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

Security Fix(es) :

* A race condition was found in the way the Linux kernel's memory
subsystem handled the copy-on-write (COW) breakage of private
read-only memory mappings. An unprivileged, local user could use this
flaw to gain write access to otherwise read-only memory mappings and
thus increase their privileges on the system. (CVE-2016-5195,
Important)

* Linux kernel built with the 802.1Q/802.1ad VLAN(CONFIG_VLAN_8021Q)
OR Virtual eXtensible Local Area Network(CONFIG_VXLAN) with
Transparent Ethernet Bridging(TEB) GRO support, is vulnerable to a
stack overflow issue. It could occur while receiving large packets via
GRO path; As an unlimited recursion could unfold in both VLAN and TEB
modules, leading to a stack corruption in the kernel. (CVE-2016-7039,
Important)

Red Hat would like to thank Phil Oester for reporting CVE-2016-5195."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHSA-2016:2107"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2016-5195"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2016-7039"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2016-8666"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:H/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:H/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:"exploit_framework_core", 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:"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-debuginfo");
  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-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:kernel-rt-debuginfo-common-x86_64");
  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-debuginfo");
  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-debuginfo");
  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:"patch_publication_date", value:"2016/10/26");
  script_set_attribute(attribute:"in_the_news", value:"true");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/10/27");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2018 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-2016:2107";
  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_exists(release:"RHEL6", rpm:"mrg-release"))) audit(AUDIT_PACKAGE_NOT_INSTALLED, "MRG");

  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debug-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debug-debuginfo-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debug-devel-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debuginfo-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-debuginfo-common-x86_64-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-devel-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", reference:"kernel-rt-doc-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", reference:"kernel-rt-firmware-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-trace-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-trace-debuginfo-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-trace-devel-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-vanilla-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-vanilla-debuginfo-3.10.0-327.rt56.198.el6")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"kernel-rt-vanilla-devel-3.10.0-327.rt56.198.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-rt / kernel-rt-debug / kernel-rt-debug-debuginfo / etc");
  }
}