Cisco ASA Software CLI Invalid Command Invocation (cisco-sa-20160817-asa-cli) (EPICBANANA)

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

include('compat.inc');

if (description)
{
  script_id(93347);
  script_version("1.13");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/04/25");

  script_cve_id("CVE-2016-6367");
  script_bugtraq_id(92520);
  script_xref(name:"EDB-ID", value:"40271");
  script_xref(name:"CISCO-BUG-ID", value:"CSCtu74257");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20160817-asa-cli");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/06/14");

  script_name(english:"Cisco ASA Software CLI Invalid Command Invocation (cisco-sa-20160817-asa-cli) (EPICBANANA)");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"The Cisco Adaptive Security Appliance (ASA) is missing a
vendor-supplied security patch. It is, therefore, affected by a flaw
in the command-line interface (CLI) parser related to processing
invalid commands. An authenticated, local attacker can exploit this,
via certain invalid commands, to cause a denial of service condition
or the execution of arbitrary code.

EPICBANANA is one of multiple Equation Group vulnerabilities and
exploits disclosed on 2016/08/14 by a group known as the Shadow
Brokers.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160817-asa-cli
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b31fa239");
  # https://www.riskbasedsecurity.com/2016/08/the-shadow-brokers-lifting-the-shadows-of-the-nsas-equation-group/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4c7e0cf3");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco Security
Advisory cisco-sa-20160817-asa-cli.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/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:L/AC:L/PR:L/UI:N/S:U/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-2016-6367");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/08/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2011/01/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/09/07");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:adaptive_security_appliance_software");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:firewall_services_module_software");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:pix_firewall_software");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2016-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_ports("Host/Cisco/ASA", "Host/Cisco/ASA/model");

  exit(0);
}

include("audit.inc");
include("cisco_func.inc");
include("cisco_kb_cmd_func.inc");

cbi = "CSCtu74257";

# Check ASA models and versions
asa = get_kb_item_or_exit('Host/Cisco/ASA');
model = get_kb_item_or_exit('Host/Cisco/ASA/model');
ver = extract_asa_version(asa);
if (isnull(ver)) audit(AUDIT_FN_FAIL, 'extract_asa_version');

if (
  model !~ '^55[0-9][0-9]($|[^0-9])'
) audit(AUDIT_HOST_NOT, "ASA 5500 5500-X");

flag = 0;
override = 0;
local_check = 0;
fixed_ver = "";
report = "";


# For each vulnerability, check for affected OS versions,
# set "fixed" os version, and perform any additional checks

if (ver =~ "^7\.2[^0-9]" || ( ver =~ "^8\.[0-4][^0-9]" && check_asa_release(version:ver, patched:"8.4(3)")))
{
  flag++;
  fixed_ver = "8.4(3)";
}
else if (ver =~ "^8\.[5-7][^0-9]" || ( ver =~ "^9\.0[^0-9]" && check_asa_release(version:ver, patched:"9.0(1)")))
{
  flag++;
  fixed_ver = "9.0(1)";
}

if (flag)
{
  security_report_cisco(
    port:     0,
    severity: SECURITY_WARNING,
    bug_id:   cbi,
    version:  ver,
    fix:      fixed_ver
  );
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");