Vulnerabilities > CVE-2017-8779 - Allocation of Resources Without Limits or Throttling vulnerability in multiple products

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2017:1267. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(100370);
  script_version("3.10");
  script_cvs_date("Date: 2019/10/24 15:35:43");

  script_cve_id("CVE-2017-8779");
  script_xref(name:"RHSA", value:"2017:1267");

  script_name(english:"RHEL 6 : rpcbind (RHSA-2017:1267)");
  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 rpcbind 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.

[Updated 16 June 2017] The packages distributed with this errata have
a bug that can cause the rpcbind utility to terminate unexpectedly at
start. RHBA-2017:1435 was released on 13 June 2017 to address this
issue.

The rpcbind utility is a server that converts Remote Procedure Call
(RPC) program numbers into universal addresses. It must be running on
the host to be able to make RPC calls on a server on that machine.

Security Fix(es) :

* It was found that due to the way rpcbind uses libtirpc (libntirpc),
a memory leak can occur when parsing specially crafted XDR messages.
An attacker sending thousands of messages to rpcbind could cause its
memory usage to grow without bound, eventually causing it to be
terminated by the OOM killer. (CVE-2017-8779)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHBA-2017:1435"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHSA-2017:1267"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2017-8779"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected rpcbind and / or rpcbind-debuginfo 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:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  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:rpcbind");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:rpcbind-debuginfo");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:6");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/05/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/05/24");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2019 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 = 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([^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-2017:1267";
  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", cpu:"i686", reference:"rpcbind-0.2.0-13.el6_9")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"s390x", reference:"rpcbind-0.2.0-13.el6_9")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"rpcbind-0.2.0-13.el6_9")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"i686", reference:"rpcbind-debuginfo-0.2.0-13.el6_9")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"s390x", reference:"rpcbind-debuginfo-0.2.0-13.el6_9")) flag++;
  if (rpm_check(release:"RHEL6", cpu:"x86_64", reference:"rpcbind-debuginfo-0.2.0-13.el6_9")) 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, "rpcbind / rpcbind-debuginfo");
  }
}