Cisco Catalyst SD-WAN Controller Authentication Bypass (cisco-sa-sdwan-rpa-EHchtZk)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(299998);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/17");

  script_cve_id("CVE-2026-20127");
  script_xref(name:"CISCO-BUG-ID", value:"CSCws52722");
  script_xref(name:"CISCO-SA", value:"cisco-sa-sdwan-rpa-EHchtZk");
  script_xref(name:"IAVA", value:"2026-A-0174");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2026/02/27");

  script_name(english:"Cisco Catalyst SD-WAN Controller Authentication Bypass (cisco-sa-sdwan-rpa-EHchtZk)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version, Cisco SD-WAN Viptela Software is affected by a vulnerability.

  - A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart,
    and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could allow an unauthenticated, remote
    attacker to bypass authentication and obtain administrative privileges on an affected system.
    (CVE-2026-20127)

  - A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart,
    and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could allow an unauthenticated, remote
    attacker to bypass authentication and obtain administrative privileges on an affected system. This
    vulnerability exists because the peering authentication mechanism in an affected system is not working
    properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system.
    A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as
    an internal, high-privileged, non-rootuser account. Using this account, the attacker could access
    NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN
    fabric. (CVE-2026-20127)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.");
  # https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-rpa-EHchtZk
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b576a300");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCws52722");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID CSCws52722");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/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-2026-20127");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_cwe_id(287);

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/02/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/02/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/02/26");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:sd-wan_firmware");
  script_set_attribute(attribute:"generated_plugin", value:"former");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CISCO");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("cisco_vedge_detect.nbin");
  script_require_keys("Cisco/Viptela/Version");

  exit(0);
}

include('ccf.inc');

var product_info = cisco::get_product_info(name:'Cisco Viptela');


var vuln_ranges = [
  { 'min_ver' : '0.0', 'fix_ver' : '20.9.8.2' },
  { 'min_ver' : '20.11', 'fix_ver' : '20.12.5.3', 'fixed_display': '20.12.5.3 or 20.12.6.1'},
  { 'min_ver' : '20.12.5', 'fix_ver' : '20.12.5.3', 'fixed_display': '20.12.5.3 or 20.12.6.1' },
  { 'min_ver' : '20.12.6', 'fix_ver' : '20.12.6.1' },
  { 'min_ver' : '20.13', 'fix_ver' : '20.15.4.2' },
  { 'min_ver' : '20.14', 'fix_ver' : '20.15.4.2' },
  { 'min_ver' : '20.15', 'fix_ver' : '20.15.4.2' },
  { 'min_ver' : '20.16', 'fix_ver' : '20.18.2.1' },
  { 'min_ver' : '20.18', 'fix_ver' : '20.18.2.1' }
];

 
var reporting = make_array(
  'port'     , 0,
  'severity' , SECURITY_HOLE,
  'bug_id'   , 'CSCws52722',
  'version'  , product_info['version'],
  'disable_caveat', TRUE
);

cisco::check_and_report(
  product_info:product_info,
  vuln_ranges:vuln_ranges,
  reporting:reporting
);