Palo Alto Networks PAN-OS 9.1.x < 9.1.3 Integer Underflow Vulnerability

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

include('compat.inc');

if (description)
{
  script_id(138221);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/10/13");

  script_cve_id("CVE-2020-2031");
  script_xref(name:"IAVA", value:"2020-A-0282-S");

  script_name(english:"Palo Alto Networks PAN-OS 9.1.x < 9.1.3 Integer Underflow Vulnerability");

  script_set_attribute(attribute:"synopsis", value:
"The remote PAN-OS host is affected by a vulnerability");
  script_set_attribute(attribute:"description", value:
"The version of Palo Alto Networks PAN-OS running on the remote host is 9.1.x prior to 9.1.3. It is, therefore, affected
by an integer underflow vulnerability in the dnsproxyd component of the PAN-OS management interface. This allows 
authenticated administrators to issue a command from the command line interface that causes the component to stop 
responding. Repeated attempts to send this request result in denial of service to all PAN-OS services by restarting 
the device and putting it into maintenance mode.

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-2020-2031");
  script_set_attribute(attribute:"see_also", value:"https://cwe.mitre.org/data/definitions/191.html");
  script_set_attribute(attribute:"solution", value:
"Upgrade to PAN-OS 9.1.3 or later");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:N/A:C");
  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:N/I:N/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-2020-2031");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_cwe_id(191);

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/07/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/07/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/09");

  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 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');

constraints = [
  { 'min_version' : '9.1.0', 'fixed_version' : '9.1.3' }
];

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