Cisco NX-OS Software Patch Signature Verification Bypass (CVE-2019-1809)

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

include('compat.inc');

if (description)
{
  script_id(501299);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/07/26");

  script_cve_id("CVE-2019-1809");

  script_name(english:"Cisco NX-OS Software Patch Signature Verification Bypass (CVE-2019-1809)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"A vulnerability in the Image Signature Verification feature of Cisco
NX-OS Software could allow an authenticated, local attacker with
administrator-level credentials to install a malicious software patch
on an affected device. The vulnerability is due to improper
verification of digital signatures for patch images. An attacker could
exploit this vulnerability by crafting an unsigned software patch to
bypass signature checks and loading it on an affected device. A
successful exploit could allow the attacker to boot a malicious
software patch image.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-nxos-psvb
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?cf9f0ff0");
  script_set_attribute(attribute:"see_also", value:"http://www.securityfocus.com/bid/108375");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/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:L/AC:L/PR:H/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-2019-1809");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_cwe_id(347);

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/05/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/05/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/07/25");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:3");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:7");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os:8");
  script_set_attribute(attribute:"generated_plugin", value:"former");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tenable.ot");

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

  script_dependencies("tenable_ot_api_integration.nasl");
  script_require_keys("Tenable.ot/Cisco");

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/Cisco');

var asset = tenable_ot::assets::get(vendor:'Cisco');

var vuln_cpes = {
    "cpe:/o:cisco:nx-os:8.1%281a%29" :
        {"versionEndExcluding" : "8.1%281a%29", "versionStartIncluding" : "7.3", "family" : "NXOS"},
    "cpe:/o:cisco:nx-os:8.3%281%29" :
        {"versionEndExcluding" : "8.3%281%29", "versionStartIncluding" : "8.2", "family" : "NXOS"},
    "cpe:/o:cisco:nx-os:7.3%283%29d1%281%29" :
        {"versionEndExcluding" : "7.3%283%29d1%281%29", "versionStartIncluding" : "7.2", "family" : "NXOS"},
    "cpe:/o:cisco:nx-os:8.2%283%29" :
        {"versionEndExcluding" : "8.2%283%29", "versionStartIncluding" : "8.0", "family" : "NXOS"},
    "cpe:/o:cisco:nx-os:3.2%283k%29" :
        {"versionEndExcluding" : "3.2%283k%29", "versionStartIncluding" : "3.1", "family" : "NXOS"}
};

tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_WARNING);