RHEL 7 : python-defusedxml and python-pysaml2 (RHSA-2017:0936)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory RHSA-2017:0936. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(210176);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/11/04");

  script_cve_id("CVE-2016-10149");
  script_xref(name:"RHSA", value:"2017:0936");

  script_name(english:"RHEL 7 : python-defusedxml and python-pysaml2 (RHSA-2017:0936)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing a security update for python-defusedxml / python-pysaml2.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 7 host has packages installed that are affected by a vulnerability as referenced in
the RHSA-2017:0936 advisory.

    The defusedxml package contains several Python-only updates for security vulnerabilities in Python's XML
    libraries. Defusedxml functions and classes can be used instead of the originals to protect against
    entity-expansion and DTD-retrieval issues.

    PySAML2 is the python implementation of SAML Version 2, containing all the functionality for building a
    SAML2 service provider or an identity provider, to be used in a WSGI environment.

    Security Fix(es):

    * An XML entity expansion vulnerability was found in python-pysaml2. A remote attacker could send a
    crafted request which would cause denial of service through resource exhaustion. (CVE-2016-10149)

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/updates/classification/#moderate");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=1415710");
  # https://access.redhat.com/security/data/csaf/v2/advisories/2017/rhsa-2017_0936.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?fb9f030f");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2017:0936");
  script_set_attribute(attribute:"solution", value:
"Update the RHEL python-defusedxml / python-pysaml2 packages based on the guidance in RHSA-2017:0936.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
  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:N/UI:N/S:U/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-10149");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(776);
  script_set_attribute(attribute:"vendor_severity", value:"Moderate");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/03/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/04/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/11/04");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:enterprise_linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:python-defusedxml");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:python-pysaml2");
  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) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('rpm.inc');
include('rhel.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'ge', os_version: os_ver, rhel_version: '7')) 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);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var constraints = [
  {
    'repo_relative_urls': [
      'content/dist/rhel/client/7/7Client/x86_64/openstack-tools/8/debug',
      'content/dist/rhel/client/7/7Client/x86_64/openstack-tools/8/os',
      'content/dist/rhel/client/7/7Client/x86_64/openstack-tools/8/source/SRPMS',
      'content/dist/rhel/server/7/7Server/x86_64/openstack-tools/8/debug',
      'content/dist/rhel/server/7/7Server/x86_64/openstack-tools/8/os',
      'content/dist/rhel/server/7/7Server/x86_64/openstack-tools/8/source/SRPMS',
      'content/dist/rhel/server/7/7Server/x86_64/openstack/8/debug',
      'content/dist/rhel/server/7/7Server/x86_64/openstack/8/os',
      'content/dist/rhel/server/7/7Server/x86_64/openstack/8/source/SRPMS',
      'content/dist/rhel/workstation/7/7Workstation/x86_64/openstack-tools/8/debug',
      'content/dist/rhel/workstation/7/7Workstation/x86_64/openstack-tools/8/os',
      'content/dist/rhel/workstation/7/7Workstation/x86_64/openstack-tools/8/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'python-defusedxml-0.5.0-1.el7ost', 'release':'7', 'el_string':'el7ost', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'openstack-'},
      {'reference':'python-pysaml2-3.0.2-3.el7ost', 'release':'7', 'el_string':'el7ost', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'openstack-'}
    ]
  }
];

var applicable_repo_urls = rhel_determine_applicable_repository_urls(constraints:constraints);
if(applicable_repo_urls == RHEL_REPOS_NO_OVERLAP_MESSAGE) exit(0, RHEL_REPO_NOT_ENABLED);

var flag = 0;
foreach var constraint_array ( constraints ) {
  var repo_relative_urls = NULL;
  if (!empty_or_null(constraint_array['repo_relative_urls'])) repo_relative_urls = constraint_array['repo_relative_urls'];
  foreach var pkg ( constraint_array['pkgs'] ) {
    var reference = NULL;
    var _release = NULL;
    var sp = NULL;
    var _cpu = NULL;
    var el_string = NULL;
    var rpm_spec_vers_cmp = NULL;
    var epoch = NULL;
    var allowmaj = NULL;
    var exists_check = NULL;
    var cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        _release &&
        rhel_decide_repo_relative_url_check(required_repo_url_list:repo_relative_urls) &&
        (applicable_repo_urls || (!exists_check || rpm_exists(release:_release, rpm:exists_check))) &&
        rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  var extra = NULL;
  if (isnull(applicable_repo_urls) || !applicable_repo_urls) extra = rpm_report_get() + redhat_report_repo_caveat();
  else extra = rpm_report_get();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_WARNING,
      extra      : extra
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'python-defusedxml / python-pysaml2');
}