MikroTik RouterOS Improper Access Control (CVE-2021-27221)

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

include('compat.inc');

if (description)
{
  script_id(502074);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/28");

  script_cve_id("CVE-2021-27221");

  script_name(english:"MikroTik RouterOS Improper Access Control (CVE-2021-27221)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"MikroTik RouterOS 6.47.9 allows remote authenticated ftp users to
create or overwrite arbitrary .rsc files via the /export command.
NOTE: the vendor's position is that this is intended behavior because
of how user policies work

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
  # https://onovy.medium.com/routeros-user-with-just-ftp-policy-can-write-to-filesystem-cve-2021-27221-e3e45d780dfe
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f1085f8f");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-27221");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/03/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/03/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/02/27");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:mikrotik:routeros:6.47.9");
  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) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/MikroTik');

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

var vuln_cpes = {
    "cpe:/o:mikrotik:routeros:6.47.9" :
        {"versionEndIncluding" : "6.47.9", "versionStartIncluding" : "6.47.9", "family" : "RouterOS"}
};

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