RHEL 7 : krb5 (RHSA-2018:3071)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Red Hat Security Advisory RHSA-2018:3071. The text 
# itself is copyright (C) Red Hat, Inc.
#

include('compat.inc');

if (description)
{
  script_id(118523);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/02/01");

  script_cve_id("CVE-2018-5729", "CVE-2018-5730");
  script_xref(name:"RHSA", value:"2018:3071");

  script_name(english:"RHEL 7 : krb5 (RHSA-2018:3071)");

  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).

Security Fix(es) :

* krb5: null dereference in kadmind or DN container check bypass by
supplying special crafted data (CVE-2018-5729)

* krb5: DN container check bypass by supplying special crafted data
(CVE-2018-5730)

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.

Additional Changes :

For detailed information on changes in this release, see the Red Hat
Enterprise Linux 7.6 Release Notes linked from the References section.");
  # https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3395ff0b");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2018:3071");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2018-5729");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/cve/cve-2018-5730");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/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:H/UI:N/S:U/C:L/I:L/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-5729");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/03/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/10/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/10/31");

  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:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Red Hat Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2018-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  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-2018:3071";
  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-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", reference:"krb5-devel-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", reference:"krb5-libs-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-pkinit-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-pkinit-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-server-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-server-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-server-ldap-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-server-ldap-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"s390x", reference:"krb5-workstation-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", cpu:"x86_64", reference:"krb5-workstation-1.15.1-34.el7")) flag++;
  if (rpm_check(release:"RHEL7", reference:"libkadm5-1.15.1-34.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");
  }
}