Palo Alto GlobalProtect Agent 5.0.x < 5.0.10 / 5.1.x < 5.1.4 Missing Certificate Validation

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

include('compat.inc');

if (description)
{
  script_id(137626);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/06/03");

  script_cve_id("CVE-2020-2033");
  script_xref(name:"IAVA", value:"2020-A-0263-S");

  script_name(english:"Palo Alto GlobalProtect Agent 5.0.x < 5.0.10 / 5.1.x < 5.1.4 Missing Certificate Validation");

  script_set_attribute(attribute:"synopsis", value:
"A VPN client installed on remote host is affected by a missing certificate validation vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of Palo Alto GlobalProtect Agent installed on the remote host is 5.0.x prior to 5.0.10, or 5.1.x
prior to 5.1.4. It is, therefore, affected by a missing certificate validation vulnerability. 
When the pre-logon feature is enabled, a missing certification validation in Palo Alto Networks 
GlobalProtect app can disclose the pre-logon authentication cookie to a man-in-the-middle attacker 
on the same local area network segment with the ability to manipulate ARP or to conduct ARP spoofing attacks. 
This allows the attacker to access the GlobalProtect Server as allowed by configured Security rules for the 
'pre-login' user. This access may be limited compared to the network access of regular users.

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-2020-2033");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Palo Alto GlobalProtect Agent 5.0.10, 5.1.4, or later");
  script_set_attribute(attribute:"agent", value:"all");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:M/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:A/AC:H/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-2020-2033");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/06/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/06/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/06/18");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:paloaltonetworks:globalprotect");
  script_set_attribute(attribute:"stig_severity", value:"II");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2020-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("palo_alto_globalprotect_agent_win_installed.nbin", "palo_alto_globalprotect_agent_mac_installed.nbin");
  script_require_keys("installed_sw/Palo Alto GlobalProtect Agent");

  exit(0);
}

include('vcf.inc');

app_info = vcf::get_app_info(app:'Palo Alto GlobalProtect Agent');

vcf::check_granularity(app_info:app_info, sig_segments:3);

constraints = [
  {'min_version' : '5.0', 'fixed_version' : '5.0.10'},
  {'min_version' : '5.1', 'fixed_version' : '5.1.4'}
];

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