Cisco ASA Insufficient Session Expiration (CVE-2021-1501)

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

include('compat.inc');

if (description)
{
  script_id(506080);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/06");

  script_cve_id("CVE-2021-1501");

  script_name(english:"Cisco ASA Insufficient Session Expiration (CVE-2021-1501)");

  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 SIP inspection engine of Cisco Adaptive
Security Appliance (ASA) Software and Cisco Firepower Threat Defense
(FTD) Software could allow an unauthenticated, remote attacker to
cause a crash and reload of an affected device, resulting in a denial
of service (DoS) condition.The vulnerability is due to a crash that
occurs during a hash lookup for a SIP pinhole connection. An attacker
could exploit this vulnerability by sending crafted SIP traffic
through an affected device. A successful exploit could allow the
attacker to cause a crash and reload of the affected device.

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-sipdos-GGwmMerC
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?79f85bf3");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-2021-1501");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(613);

  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:9.8" :
        {"versionEndExcluding" : "9.8.4.34", "versionStartIncluding" : "9.8", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.9" :
        {"versionEndExcluding" : "9.9.2.85", "versionStartIncluding" : "9.9", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.10" :
        {"versionEndExcluding" : "9.12.4.18", "versionStartIncluding" : "9.10", "family" : "CiscoFirepower"},
    "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" : "9.15.1.15", "versionStartIncluding" : "9.15", "family" : "CiscoFirepower"}
};

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