Splunk Enterprise 8.1.x < 8.1.6 MFA Bypass

##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(161707);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/09/05");

  script_cve_id("CVE-2021-26253");
  script_xref(name:"IAVA", value:"2022-A-0219-S");

  script_name(english:"Splunk Enterprise 8.1.x < 8.1.6 MFA Bypass");

  script_set_attribute(attribute:"synopsis", value:
"An application running on a remote web server host may be affected by an MFA bypass vulnerability.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version number, the version of Splunk running on the remote web server is Splunk
Enterprise 8.1.x prior to 8.1.6. It is, therefore, affected by a vulnerability in Splunk Enterprise's implementation of
DUO MFA that allows for bypassing the MFA verification. The vulnerability impacts Splunk Enterprise instances configured
to use DUO MFA and does not impact or affect a DUO product or service.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://www.splunk.com/en_us/product-security/announcements/svd-2022-0504.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?52d93bf3");
  script_set_attribute(attribute:"solution", value:
"Upgrade Splunk Enterprise to version 8.1.6, 8.2.0, or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/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:H/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-26253");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2022/05/03");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/05/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/05/31");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:splunk:splunk");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_set_attribute(attribute:"agent", value:"unix");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CGI abuses");

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

  script_dependencies("splunk_web_detect.nasl", "splunkd_detect.nasl", "macos_splunk_installed.nbin");
  script_require_keys("installed_sw/Splunk");

  exit(0);
}

include('vcf_extras_splunk.inc');

var app_info = vcf::splunk::get_app_info();

var constraints = [
  { 'min_version' : '8.1', 'fixed_version' : '8.1.6', 'fixed_display' : '8.1.6 / 8.2.0', 'license' : 'Enterprise' }
];

vcf::splunk::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_WARNING);