Cisco ASA OS Command Injection (CVE-2021-1476)

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

include('compat.inc');

if (description)
{
  script_id(506077);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/06");

  script_cve_id("CVE-2021-1476");

  script_name(english:"Cisco ASA OS Command Injection (CVE-2021-1476)");

  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 CLI of Cisco Adaptive Security Appliance (ASA)
Software and Cisco Firepower Threat Defense (FTD) Software could allow
an authenticated, local attacker to execute arbitrary commands on the
underlying operating system (OS) of an affected device. The
vulnerability is due to insufficient input validation of commands that
are supplied by the user. An attacker could exploit this vulnerability
by authenticating to a device and submitting crafted input for
specific commands. A successful exploit could allow the attacker to
execute commands on the underlying OS with root privileges. To exploit
this vulnerability, an attacker must have valid administrator-level
credentials.

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-asa-ftd-cmd-inj-SELprvG
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?de3f6c67");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  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-2021-1476");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(78);

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/04/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/04/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/05");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:adaptive_security_appliance_software: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) 2026 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:adaptive_security_appliance_software:9.13" :
        {"versionEndExcluding" : "9.13.1.21", "versionStartIncluding" : "9.13", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.14" :
        {"versionEndExcluding" : "9.14.2.13", "versionStartIncluding" : "9.14", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.15" :
        {"versionEndExcluding" : "9.15.1.10", "versionStartIncluding" : "9.15", "family" : "CiscoFirepower"}
};

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