RHEL 7 : krb5 (RHSA-2016:2591)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2016:2591. The text 
# itself is copyright (C) Red Hat, Inc.
#

include("compat.inc");

if (description)
{
  script_id(94554);
  script_version("2.15");
  script_cvs_date("Date: 2019/10/24 15:35:42");

  script_cve_id("CVE-2016-3119", "CVE-2016-3120");
  script_xref(name:"RHSA", value:"2016:2591");

  script_name(english:"RHEL 7 : krb5 (RHSA-2016:2591)");
  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 krb5 is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security
impact of Low. 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.

Kerberos is a network authentication system, which can improve the
security of your network by eliminating the insecure practice of
sending passwords over the network in unencrypted form. It allows
clients and servers to authenticate to each other with the help of a
trusted third party, the Kerberos key distribution center (KDC).

The following packages have been upgraded to a newer upstream version:
krb5 (1.14.1). (BZ#1292153)

Security Fix(es) :

* A NULL pointer dereference flaw was found in MIT Kerberos kadmind
service. An authenticated attacker with permission to modify a
principal entry could use this flaw to cause kadmind to dereference a
NULL pointer and crash by supplying an empty DB argument to the
modify_principal command, if kadmind was configured to use the LDAP
KDB module. (CVE-2016-3119)

* A NULL pointer dereference flaw was found in MIT Kerberos krb5kdc
service. An authenticated attacker could use this flaw to cause
krb5kdc to dereference a NULL pointer and crash by making an S4U2Self
request, if the restrict_anonymous_to_tgt option was set to true.
(CVE-2016-3120)

Additional Changes :

For detailed information on changes in this release, see the Red Hat
Enterprise Linux 7.3 Release Notes linked from the References section."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/errata/RHSA-2016:2591"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2016-3119"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://access.redhat.com/security/cve/cve-2016-3120"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:krb5-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:krb5-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:krb5-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:krb5-pkinit");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:krb5-server");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:krb5-server-ldap");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:krb5-workstation");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:libkadm5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.3");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7.7");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/03/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/11/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/11/04");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2019 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:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Red Hat 7.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-2016:2591";
  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:"RHEL7", reference:"krb5-debuginfo-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", reference:"krb5-devel-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", reference:"krb5-libs-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-pkinit-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-pkinit-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-server-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-server-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-server-ldap-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-server-ldap-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-workstation-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-workstation-1.14.1-26.el7")) flag++;

  if (rpm_check(release:"RHEL7", reference:"libkadm5-1.14.1-26.el7")) 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, "krb5-debuginfo / krb5-devel / krb5-libs / krb5-pkinit / krb5-server / etc");
  }
}