Palo Alto Networks PAN-OS 8.0.x < 8.1.15 / 8.1.x < 8.1.15 / 9.0.x < 9.0.9 / 9.1.x < 9.1.3 Authentication Bypass in SAML Authentication (CVE-2020-2021)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(137880);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/04/25");

  script_cve_id("CVE-2020-2021");
  script_xref(name:"IAVA", value:"2020-A-0282-S");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/04/15");
  script_xref(name:"CEA-ID", value:"CEA-2020-0054");

  script_name(english:"Palo Alto Networks PAN-OS 8.0.x < 8.1.15 / 8.1.x < 8.1.15 / 9.0.x < 9.0.9 / 9.1.x < 9.1.3 Authentication Bypass in SAML Authentication (CVE-2020-2021)");

  script_set_attribute(attribute:"synopsis", value:
"The remote PAN-OS host is affected by an authentication bypass vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of Palo Alto Networks PAN-OS running on the remote host is 8.0.x prior to 8.1.15 or 8.1.x prior to 8.1.15 or
9.0.x prior to 9.0.9 or 9.1.x prior to 9.1.3. It is, therefore, affected by a SAML authentication bypass vulnerability.

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://security.paloaltonetworks.com/CVE-2020-2021");
  script_set_attribute(attribute:"see_also", value:"https://cwe.mitre.org/data/definitions/347.html");
  script_set_attribute(attribute:"solution", value:
"Upgrade to PAN-OS 8.1.15 / 8.1.15 / 9.0.9 / 9.1.3 or later");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-2021");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_cwe_id(347);

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/06/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/06/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/06/29");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:paloaltonetworks:pan-os");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Palo Alto Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2020-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("palo_alto_version.nbin");
  script_require_keys("Host/Palo_Alto/Firewall/Version", "Host/Palo_Alto/Firewall/Full_Version", "Host/Palo_Alto/Firewall/Source");

  exit(0);
}

include('vcf.inc');
include('vcf_extras.inc');

vcf::palo_alto::initialize();

app_name = 'Palo Alto Networks PAN-OS';

app_info = vcf::get_app_info(app:app_name, kb_ver:'Host/Palo_Alto/Firewall/Full_Version', kb_source:'Host/Palo_Alto/Firewall/Source');

# we can't check if SAML auth is in use
# we also can't check if the 'Validate Identity Provider Certificate' option is disabled
# However, customers rarely run paranoid checks (~15%), so let's remove paranoid (see RES-41791)
# if (report_paranoia < 2) audit(AUDIT_PARANOID);

constraints = [
  { 'min_version' : '8.0.0', 'fixed_version' : '8.1.15' },
  { 'min_version' : '8.1.0', 'fixed_version' : '8.1.15' },
  { 'min_version' : '9.0.0', 'fixed_version' : '9.0.9' },
  { 'min_version' : '9.1.0', 'fixed_version' : '9.1.3' }
];

vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);